diff --git a/api/agents/prompts/memory_prompts.py b/api/agents/prompts/memory_prompts.py
index d80c0c9..620ad1b 100644
--- a/api/agents/prompts/memory_prompts.py
+++ b/api/agents/prompts/memory_prompts.py
@@ -43,7 +43,6 @@ STAGE_TO_ORDER = {
     "summary": 7,
 }
 
-
 def get_system_prompt() -> str:
     """获取整理 Agent 的系统提示词"""
     return """你是一位专业的传记作家和文字编辑，擅长将口语化的对话内容整理成优雅的书面语回忆录章节。
@@ -323,4 +322,3 @@ def get_narrative_prompt(
 
 只输出新对话内容的改写结果（包含图片占位符）。如果对话中没有值得记录的人生经历内容，输出空字符串。
 """
-
diff --git a/api/routers/chapters.py b/api/routers/chapters.py
index 42355a0..f249e26 100644
--- a/api/routers/chapters.py
+++ b/api/routers/chapters.py
@@ -1,6 +1,8 @@
 """
 章节相关 API 路由
 """
+import logging
+import os
 from typing import List, Optional
 
 from fastapi import APIRouter, Depends, HTTPException, Query
@@ -12,11 +14,48 @@ from database.models import Chapter as ChapterModel
 from database.models import User as UserModel
 from middleware.auth import get_current_user
 from agents.prompts.memory_prompts import CHAPTER_CATEGORIES, CHAPTER_ORDER, STAGE_TO_ORDER
+from services.memoir_images.storage import (
+    TencentCosStorageService,
+    normalize_cos_url,
+    resolve_image_storage_key,
+)
 
 router = APIRouter(prefix="/api/chapters", tags=["chapters"])
+logger = logging.getLogger(__name__)
+
+
+def _normalize_image_assets(images: list[dict] | None) -> list[dict]:
+    bucket = os.getenv("TENCENT_COS_BUCKET", "")
+    region = os.getenv("TENCENT_COS_REGION", "")
+    base_url = os.getenv("TENCENT_COS_BASE_URL", "")
+    storage = TencentCosStorageService.from_env()
+    normalized_assets: list[dict] = []
+
+    for item in (images or []):
+        asset = dict(item)
+        normalized_url = normalize_cos_url(
+            asset.get("url"),
+            bucket=bucket,
+            region=region,
+            base_url=base_url,
+        )
+        storage_key = resolve_image_storage_key(asset)
+        if asset.get("status") == "completed" and storage_key:
+            try:
+                asset["url"] = storage.get_download_url(storage_key)
+            except Exception as exc:
+                logger.warning("章节图片签名失败: key=%s, error=%s", storage_key, exc)
+                asset["url"] = normalized_url
+        else:
+            asset["url"] = normalized_url
+        asset.pop("storage_key", None)
+        normalized_assets.append(asset)
+
+    return normalized_assets
 
 
 def _chapter_to_dict(ch: ChapterModel) -> dict:
+    normalized_images = _normalize_image_assets(ch.images)
     return {
         "id": ch.id,
         "title": ch.title,
@@ -24,7 +63,7 @@ def _chapter_to_dict(ch: ChapterModel) -> dict:
         "order_index": ch.order_index,
         "status": ch.status,
         "category": ch.category,
-        "images": ch.images or [],
+        "images": normalized_images,
         "updated_at": ch.updated_at.isoformat() if ch.updated_at else None,
         "is_new": ch.is_new,
         "source_segments": ch.source_segments or [],
@@ -105,7 +144,7 @@ async def get_chapter(
         "order_index": chapter.order_index,
         "status": chapter.status,
         "category": chapter.category,
-        "images": chapter.images or [],
+        "images": _normalize_image_assets(chapter.images),
         "updated_at": chapter.updated_at.isoformat() if chapter.updated_at else None,
         "is_new": chapter.is_new,
         "source_segments": chapter.source_segments or [],
@@ -151,4 +190,3 @@ async def regenerate_chapter(
     
     # TODO: 实现重新整理逻辑
     return {"status": "ok", "message": "Chapter regeneration triggered"}
-
diff --git a/api/services/memoir_images/parser.py b/api/services/memoir_images/parser.py
index 7854f66..18f511e 100644
--- a/api/services/memoir_images/parser.py
+++ b/api/services/memoir_images/parser.py
@@ -1,13 +1,16 @@
 import re
 from typing import Any
 
-PLACEHOLDER_RE = re.compile(r"\{\{\{\{IMAGE:(.*?)\}\}\}\}")
+PLACEHOLDER_RE = re.compile(
+    r"\{\{\{\{IMAGE:(.*?)\}\}\}\}|\{\{IMAGE:(.*?)\}\}",
+    re.DOTALL,
+)
 
 
 def parse_image_placeholders(content: str, max_images: int) -> list[dict[str, Any]]:
     items: list[dict[str, Any]] = []
     for match in PLACEHOLDER_RE.finditer(content or ""):
-        description = match.group(1).strip()
+        description = (match.group(1) or match.group(2) or "").strip()
         if not description:
             continue
         items.append(
diff --git a/api/services/memoir_images/settings.py b/api/services/memoir_images/settings.py
index ec1e9df..e820e70 100644
--- a/api/services/memoir_images/settings.py
+++ b/api/services/memoir_images/settings.py
@@ -20,7 +20,7 @@ class MemoirImageSettings:
             max_per_chapter=int(os.getenv("MEMOIR_IMAGE_MAX_PER_CHAPTER", "2")),
             provider=os.getenv("MEMOIR_IMAGE_PROVIDER", "liblib"),
             default_style=os.getenv("MEMOIR_IMAGE_STYLE_DEFAULT", "watercolor"),
-            default_size=os.getenv("MEMOIR_IMAGE_SIZE_DEFAULT", "1024x1024"),
+            default_size=os.getenv("MEMOIR_IMAGE_SIZE_DEFAULT", "1280x720"),
             poll_interval_seconds=int(os.getenv("MEMOIR_IMAGE_POLL_INTERVAL", "3")),
             max_attempts=int(os.getenv("MEMOIR_IMAGE_MAX_ATTEMPTS", "60")),
             liblib_template_uuid=os.getenv(
diff --git a/api/services/memoir_images/storage.py b/api/services/memoir_images/storage.py
index ea41b8e..72bc783 100644
--- a/api/services/memoir_images/storage.py
+++ b/api/services/memoir_images/storage.py
@@ -1,12 +1,75 @@
 import os
+from urllib.parse import urlparse, urlunparse
 
 from qcloud_cos import CosConfig, CosS3Client
 
 
+def normalize_cos_base_url(base_url: str, bucket: str, region: str) -> str:
+    candidate = (base_url or "").rstrip("/")
+    if not candidate and bucket and region:
+        candidate = f"https://{bucket}.cos.{region}.myqcloud.com"
+    if not candidate:
+        return ""
+
+    parsed = urlparse(candidate)
+    duplicated_appid_host = f"{bucket}-appid.cos." if bucket else ""
+    if duplicated_appid_host and parsed.netloc.startswith(duplicated_appid_host):
+        parsed = parsed._replace(
+            netloc=parsed.netloc.replace(duplicated_appid_host, f"{bucket}.cos.", 1),
+            path=parsed.path.rstrip("/"),
+        )
+        return urlunparse(parsed).rstrip("/")
+
+    return candidate
+
+
+def normalize_cos_url(url: str | None, bucket: str, region: str, base_url: str | None = None) -> str | None:
+    if not url:
+        return url
+
+    parsed = urlparse(url)
+    if not parsed.scheme or not parsed.netloc:
+        return url
+
+    normalized_base = normalize_cos_base_url(
+        base_url or f"{parsed.scheme}://{parsed.netloc}",
+        bucket=bucket,
+        region=region,
+    )
+    if not normalized_base:
+        return url
+
+    normalized_parsed = urlparse(normalized_base)
+    return urlunparse(parsed._replace(scheme=normalized_parsed.scheme, netloc=normalized_parsed.netloc))
+
+
+def resolve_image_storage_key(image: dict | None) -> str | None:
+    if not image:
+        return None
+
+    explicit_key = image.get("storage_key")
+    if explicit_key:
+        return explicit_key
+
+    url = image.get("url")
+    if not url:
+        return None
+
+    parsed = urlparse(url)
+    if parsed.scheme and parsed.netloc:
+        key = parsed.path.lstrip("/")
+        return key or None
+
+    return str(url).lstrip("/") or None
+
+
 class TencentCosStorageService:
     def __init__(self, secret_id: str, secret_key: str, region: str, bucket: str, base_url: str):
+        self.secret_id = secret_id
+        self.secret_key = secret_key
         self.bucket = bucket
-        self.base_url = base_url.rstrip("/")
+        self.region = region
+        self.base_url = normalize_cos_base_url(base_url, bucket=bucket, region=region)
         config = CosConfig(Region=region, SecretId=secret_id, SecretKey=secret_key)
         self.client = CosS3Client(config)
 
@@ -19,6 +82,13 @@ class TencentCosStorageService:
         )
         return f"{self.base_url}/{key}"
 
+    def get_download_url(self, key: str, expires: int = 3600) -> str:
+        return self.client.get_presigned_download_url(
+            Bucket=self.bucket,
+            Key=key,
+            Expired=expires,
+        )
+
     @classmethod
     def from_env(cls) -> "TencentCosStorageService":
         return cls(
diff --git a/api/services/pdf_service.py b/api/services/pdf_service.py
index bf7715d..77a91dd 100644
--- a/api/services/pdf_service.py
+++ b/api/services/pdf_service.py
@@ -13,6 +13,7 @@ from reportlab.platypus import SimpleDocTemplate, Paragraph, Spacer, PageBreak,
 from reportlab.pdfbase import pdfmetrics
 from reportlab.pdfbase.cidfonts import UnicodeCIDFont
 from io import BytesIO
+from services.memoir_images.storage import TencentCosStorageService, resolve_image_storage_key
 
 logger = logging.getLogger(__name__)
 
@@ -42,6 +43,23 @@ def split_content_blocks(content: str, images: list[dict]) -> list[dict]:
     return blocks
 
 
+def _prepare_pdf_image_assets(images: list[dict]) -> list[dict]:
+    storage = TencentCosStorageService.from_env()
+    prepared_assets: list[dict] = []
+
+    for item in images or []:
+        asset = dict(item)
+        storage_key = resolve_image_storage_key(asset)
+        if asset.get("status") == "completed" and storage_key:
+            try:
+                asset["url"] = storage.get_download_url(storage_key)
+            except Exception as exc:
+                logger.warning(f"PDF 图片签名失败: key={storage_key}, error={exc}")
+        prepared_assets.append(asset)
+
+    return prepared_assets
+
+
 class PDFService:
     """PDF 生成服务"""
 
@@ -108,7 +126,7 @@ class PDFService:
             story.append(Paragraph(chapter.title, heading_style))
             story.append(Spacer(1, 0.2 * inch))
 
-            images = getattr(chapter, "images", None) or []
+            images = _prepare_pdf_image_assets(getattr(chapter, "images", None) or [])
             blocks = split_content_blocks(chapter.content, images)
 
             for block in blocks:
diff --git a/api/tasks/memoir_tasks.py b/api/tasks/memoir_tasks.py
index 5517fcc..cc382fc 100644
--- a/api/tasks/memoir_tasks.py
+++ b/api/tasks/memoir_tasks.py
@@ -106,7 +106,9 @@ def _merge_chapter_image_assets(
             merged_item["size"] = merged_item.get("size") or size
             merged_item["created_at"] = merged_item.get("created_at") or now_iso
             merged_item["updated_at"] = merged_item.get("updated_at") or now_iso
-            if merged_item.get("status") == "completed" and not merged_item.get("url"):
+            if merged_item.get("status") == "completed" and not (
+                merged_item.get("storage_key") or merged_item.get("url")
+            ):
                 merged_item["status"] = "failed"
                 merged_item["error"] = merged_item.get("error") or "missing image url"
         else:
@@ -131,6 +133,7 @@ def initialize_chapter_images(chapter) -> list[dict]:
     settings = MemoirImageSettings.from_env()
     if not settings.enabled:
         chapter.images = []
+        logger.info(f"章节图片初始化跳过: chapter={chapter.id}, enabled=false")
         return chapter.images
 
     prompt_service = MemoirImagePromptService(llm=None, settings=settings)
@@ -144,6 +147,13 @@ def initialize_chapter_images(chapter) -> list[dict]:
         size=settings.default_size,
         now_iso=datetime.now(timezone.utc).isoformat(),
     )
+    logger.info(
+        "章节图片初始化完成: chapter=%s, placeholders=%d, images=%d, statuses=%s",
+        chapter.id,
+        len(placeholders),
+        len(chapter.images or []),
+        [item.get("status") for item in (chapter.images or [])],
+    )
     return chapter.images
 
 
@@ -479,6 +489,7 @@ def process_memoir_segments(self, user_id: str, segment_ids: List[str]):
 
             for chapter_id in sorted(chapters_to_enqueue):
                 try:
+                    logger.info(f"派发章节补图任务: chapter={chapter_id}")
                     generate_chapter_images.delay(chapter_id)
                 except Exception as exc:
                     logger.warning(f"补图任务派发失败: chapter={chapter_id}, error={exc}")
@@ -599,6 +610,7 @@ def generate_chapter_images(self, chapter_id: str):
     try:
         chapter = db.get(Chapter, chapter_id)
         if not chapter or not chapter.images:
+            logger.info(f"章节补图跳过: chapter={chapter_id}, reason=no_images")
             return {"status": "no_images"}
 
         settings = MemoirImageSettings.from_env()
@@ -606,9 +618,16 @@ def generate_chapter_images(self, chapter_id: str):
         provider = LiblibImageProvider(template_uuid=settings.liblib_template_uuid)
         storage = TencentCosStorageService.from_env()
         images = [dict(item) for item in (chapter.images or [])]
+        pending_count = sum(1 for item in images if item.get("status") in {"pending", "failed"})
+        logger.info(
+            "章节补图开始: chapter=%s, total_images=%d, pending_images=%d",
+            chapter_id,
+            len(images),
+            pending_count,
+        )
 
         for index, item in enumerate(images):
-            if item.get("status") == "completed" and item.get("url"):
+            if item.get("status") == "completed" and (item.get("storage_key") or item.get("url")):
                 continue
             if item.get("status") not in {"pending", "failed"}:
                 continue
@@ -643,12 +662,19 @@ def generate_chapter_images(self, chapter_id: str):
                     )
                 image_bytes = provider.download_image(job)
                 key = build_cos_key(chapter.user_id, chapter.id, current_item["index"], prompt_data["prompt"])
+                current_item["storage_key"] = key
                 current_item["url"] = storage.upload_bytes(image_bytes, key, "image/png")
                 current_item["prompt"] = prompt_data["prompt"]
                 current_item["style"] = prompt_data["style"]
                 current_item["size"] = prompt_data["size"]
                 current_item["status"] = "completed"
                 current_item["error"] = None
+                logger.info(
+                    "章节补图成功: chapter=%s, index=%s, url=%s",
+                    chapter_id,
+                    current_item.get("index"),
+                    current_item["url"],
+                )
             except Exception as exc:
                 current_item["status"] = "failed"
                 current_item["error"] = str(exc)
diff --git a/api/tests/test_chapters_router_images.py b/api/tests/test_chapters_router_images.py
new file mode 100644
index 0000000..62c697a
--- /dev/null
+++ b/api/tests/test_chapters_router_images.py
@@ -0,0 +1,58 @@
+import os
+import unittest
+from unittest.mock import Mock, patch
+
+from api.routers.chapters import _chapter_to_dict
+
+
+class ChaptersRouterImagesTest(unittest.TestCase):
+    @patch("api.routers.chapters.TencentCosStorageService")
+    @patch.dict(
+        os.environ,
+        {
+            "TENCENT_COS_BUCKET": "life-echo-dev-1319381411",
+            "TENCENT_COS_REGION": "ap-shanghai",
+            "TENCENT_COS_BASE_URL": "https://life-echo-dev-1319381411.cos.ap-shanghai.myqcloud.com",
+        },
+        clear=False,
+    )
+    def test_chapter_to_dict_returns_signed_image_urls_for_response(self, storage_cls):
+        storage = Mock()
+        storage.get_download_url.return_value = "https://signed.example.com/memoirs/u1/c1/0-demo.png?sig=123"
+        storage_cls.from_env.return_value = storage
+
+        chapter = type(
+            "ChapterStub",
+            (),
+            {
+                "id": "chapter-1",
+                "title": "童年的夏天",
+                "content": "{{IMAGE:南方小镇的青石板路}}",
+                "order_index": 0,
+                "status": "completed",
+                "category": "childhood",
+                "images": [
+                    {
+                        "index": 0,
+                        "placeholder": "{{IMAGE:南方小镇的青石板路}}",
+                        "description": "南方小镇的青石板路",
+                        "status": "completed",
+                        "prompt": "A serene southern China town",
+                        "url": "https://life-echo-dev-1319381411.cos.ap-shanghai.myqcloud.com/memoirs/u1/c1/0-demo.png",
+                        "storage_key": "memoirs/u1/c1/0-demo.png",
+                    }
+                ],
+                "updated_at": None,
+                "is_new": False,
+                "source_segments": [],
+            },
+        )()
+
+        payload = _chapter_to_dict(chapter)
+
+        self.assertEqual(
+            payload["images"][0]["url"],
+            "https://signed.example.com/memoirs/u1/c1/0-demo.png?sig=123",
+        )
+        self.assertEqual(payload["images"][0]["prompt"], "A serene southern China town")
+        self.assertNotIn("storage_key", payload["images"][0])
diff --git a/api/tests/test_generate_chapter_images_task.py b/api/tests/test_generate_chapter_images_task.py
index 08cc1d0..bc723ce 100644
--- a/api/tests/test_generate_chapter_images_task.py
+++ b/api/tests/test_generate_chapter_images_task.py
@@ -58,6 +58,7 @@ class GenerateChapterImagesTaskTest(unittest.TestCase):
         generate_chapter_images.run("chapter-1")
 
         self.assertEqual(chapter.images[0]["status"], "completed")
+        self.assertEqual(chapter.images[0]["storage_key"], "memoirs/user-1/chapter-1/0-7e1f860790.png")
         self.assertEqual(chapter.images[0]["url"], "https://cos.example.com/memoirs/u1/c1/0.png")
         self.assertEqual(chapter.images[0]["prompt"], "A serene southern China town")
         db.commit.assert_called()
diff --git a/api/tests/test_memoir_image_bootstrap.py b/api/tests/test_memoir_image_bootstrap.py
index 2270eda..d076d5d 100644
--- a/api/tests/test_memoir_image_bootstrap.py
+++ b/api/tests/test_memoir_image_bootstrap.py
@@ -66,3 +66,23 @@ class MemoirImageBootstrapTest(unittest.TestCase):
         self.assertEqual(assets[0]["url"], "https://cos.example.com/existing.png")
         self.assertEqual(assets[1]["status"], "pending")
         self.assertEqual(assets[1]["description"], "奶奶坐在院子里的藤椅上")
+
+    def test_initialize_chapter_images_accepts_double_brace_placeholders(self):
+        chapter = type(
+            "ChapterStub",
+            (),
+            {
+                "id": "chapter-1",
+                "title": "童年的夏天",
+                "category": "childhood",
+                "content": "开头。\n\n{{IMAGE:1938年初的上海弄堂口，冬日萧瑟}}\n\n结尾。",
+                "images": [],
+            },
+        )()
+
+        with unittest.mock.patch.dict(os.environ, {"MEMOIR_IMAGE_ENABLED": "true"}, clear=False):
+            assets = initialize_chapter_images(chapter)
+
+        self.assertEqual(len(assets), 1)
+        self.assertEqual(assets[0]["status"], "pending")
+        self.assertEqual(assets[0]["placeholder"], "{{IMAGE:1938年初的上海弄堂口，冬日萧瑟}}")
diff --git a/api/tests/test_memoir_image_parser.py b/api/tests/test_memoir_image_parser.py
index 3e29c0f..b1a1a92 100644
--- a/api/tests/test_memoir_image_parser.py
+++ b/api/tests/test_memoir_image_parser.py
@@ -43,3 +43,12 @@ class MemoirImageParserTest(unittest.TestCase):
         self.assertEqual(assets[0]["status"], "pending")
         self.assertEqual(assets[0]["provider"], "liblib")
         self.assertEqual(assets[0]["url"], None)
+
+    def test_parse_image_placeholders_accepts_double_brace_variant(self):
+        content = "开头。\n\n{{IMAGE:1938年初的上海弄堂口，冬日萧瑟}}\n\n结尾。"
+
+        items = parse_image_placeholders(content, max_images=2)
+
+        self.assertEqual(len(items), 1)
+        self.assertEqual(items[0]["placeholder"], "{{IMAGE:1938年初的上海弄堂口，冬日萧瑟}}")
+        self.assertEqual(items[0]["description"], "1938年初的上海弄堂口，冬日萧瑟")
diff --git a/api/tests/test_memoir_image_prompting.py b/api/tests/test_memoir_image_prompting.py
index a267787..e745b74 100644
--- a/api/tests/test_memoir_image_prompting.py
+++ b/api/tests/test_memoir_image_prompting.py
@@ -15,6 +15,7 @@ class MemoirImagePromptingTest(unittest.TestCase):
             default_size="1024x1024",
             poll_interval_seconds=3,
             max_attempts=20,
+            liblib_template_uuid="tpl-uuid",
         )
         service = MemoirImagePromptService(llm=None, settings=settings)
 
@@ -39,6 +40,7 @@ class MemoirImagePromptingTest(unittest.TestCase):
             default_size="1024x1024",
             poll_interval_seconds=3,
             max_attempts=20,
+            liblib_template_uuid="tpl-uuid",
         )
         llm = Mock()
         llm.invoke.return_value.content = (
diff --git a/api/tests/test_memoir_image_storage.py b/api/tests/test_memoir_image_storage.py
index 9e771c1..3f8262e 100644
--- a/api/tests/test_memoir_image_storage.py
+++ b/api/tests/test_memoir_image_storage.py
@@ -1,7 +1,11 @@
 import unittest
 from unittest.mock import Mock, patch
 
-from api.services.memoir_images.storage import TencentCosStorageService
+from api.services.memoir_images.storage import (
+    TencentCosStorageService,
+    normalize_cos_url,
+    resolve_image_storage_key,
+)
 
 
 class MemoirImageStorageTest(unittest.TestCase):
@@ -28,3 +32,80 @@ class MemoirImageStorageTest(unittest.TestCase):
             "https://memoir-1250000000.cos.ap-shanghai.myqcloud.com/memoirs/u1/c1/0-demo.png",
         )
         client.put_object.assert_called_once()
+
+    @patch("api.services.memoir_images.storage.CosS3Client")
+    def test_upload_bytes_normalizes_duplicate_appid_suffix_in_base_url(self, client_cls):
+        client = Mock()
+        client_cls.return_value = client
+        storage = TencentCosStorageService(
+            secret_id="id",
+            secret_key="key",
+            region="ap-shanghai",
+            bucket="life-echo-dev-1319381411",
+            base_url="https://life-echo-dev-1319381411-appid.cos.ap-shanghai.myqcloud.com",
+        )
+
+        url = storage.upload_bytes(
+            image_bytes=b"png-bytes",
+            key="memoirs/u1/c1/0-demo.png",
+            content_type="image/png",
+        )
+
+        self.assertEqual(
+            url,
+            "https://life-echo-dev-1319381411.cos.ap-shanghai.myqcloud.com/memoirs/u1/c1/0-demo.png",
+        )
+        client.put_object.assert_called_once()
+
+    def test_normalize_cos_url_repairs_existing_duplicate_appid_host(self):
+        normalized = normalize_cos_url(
+            "https://life-echo-dev-1319381411-appid.cos.ap-shanghai.myqcloud.com/memoirs/u1/c1/0-demo.png",
+            bucket="life-echo-dev-1319381411",
+            region="ap-shanghai",
+        )
+
+        self.assertEqual(
+            normalized,
+            "https://life-echo-dev-1319381411.cos.ap-shanghai.myqcloud.com/memoirs/u1/c1/0-demo.png",
+        )
+
+    @patch("api.services.memoir_images.storage.CosS3Client")
+    def test_get_download_url_returns_presigned_download_url(self, client_cls):
+        client = Mock()
+        client.get_presigned_download_url.return_value = "https://cos.example.com/0.png?q-sign-algorithm=sha1"
+        client_cls.return_value = client
+        storage = TencentCosStorageService(
+            secret_id="id",
+            secret_key="key",
+            region="ap-shanghai",
+            bucket="life-echo-dev-1319381411",
+            base_url="https://life-echo-dev-1319381411.cos.ap-shanghai.myqcloud.com",
+        )
+
+        url = storage.get_download_url("memoirs/u1/c1/0-demo.png", expires=1800)
+
+        self.assertEqual(url, "https://cos.example.com/0.png?q-sign-algorithm=sha1")
+        client.get_presigned_download_url.assert_called_once_with(
+            Bucket="life-echo-dev-1319381411",
+            Key="memoirs/u1/c1/0-demo.png",
+            Expired=1800,
+        )
+
+    def test_resolve_image_storage_key_prefers_explicit_storage_key(self):
+        key = resolve_image_storage_key(
+            {
+                "storage_key": "memoirs/u1/c1/0-demo.png",
+                "url": "https://life-echo-dev-1319381411.cos.ap-shanghai.myqcloud.com/other.png",
+            }
+        )
+
+        self.assertEqual(key, "memoirs/u1/c1/0-demo.png")
+
+    def test_resolve_image_storage_key_derives_key_from_existing_url(self):
+        key = resolve_image_storage_key(
+            {
+                "url": "https://life-echo-dev-1319381411.cos.ap-shanghai.myqcloud.com/memoirs/u1/c1/0-demo.png?q-sign-algorithm=sha1"
+            }
+        )
+
+        self.assertEqual(key, "memoirs/u1/c1/0-demo.png")
diff --git a/api/tests/test_pdf_service_images.py b/api/tests/test_pdf_service_images.py
index 7fd5914..f77cc94 100644
--- a/api/tests/test_pdf_service_images.py
+++ b/api/tests/test_pdf_service_images.py
@@ -6,7 +6,12 @@ from api.services.pdf_service import PDFService
 
 class PDFServiceImagesTest(unittest.IsolatedAsyncioTestCase):
     @patch("api.services.pdf_service.httpx.AsyncClient")
-    async def test_generate_pdf_embeds_completed_images_and_removes_placeholders(self, async_client_cls):
+    @patch("api.services.pdf_service.TencentCosStorageService")
+    async def test_generate_pdf_embeds_completed_images_and_removes_placeholders(
+        self,
+        storage_cls,
+        async_client_cls,
+    ):
         png_bytes = (
             b"\x89PNG\r\n\x1a\n\x00\x00\x00\rIHDR\x00\x00\x00\x01\x00\x00\x00\x01"
             b"\x08\x02\x00\x00\x00\x90wS\xde\x00\x00\x00\x0cIDATx\x9cc```\x00\x00"
@@ -20,6 +25,9 @@ class PDFServiceImagesTest(unittest.IsolatedAsyncioTestCase):
         mock_client.get.return_value = mock_response
         async_client_cls.return_value.__aenter__ = AsyncMock(return_value=mock_client)
         async_client_cls.return_value.__aexit__ = AsyncMock(return_value=False)
+        storage = MagicMock()
+        storage.get_download_url.return_value = "https://signed.example.com/0.png?sig=123"
+        storage_cls.from_env.return_value = storage
 
         service = PDFService()
         book = type("BookStub", (), {"title": "我的回忆录"})()
@@ -33,7 +41,8 @@ class PDFServiceImagesTest(unittest.IsolatedAsyncioTestCase):
                     {
                         "index": 0,
                         "placeholder": "{{{{IMAGE:南方小镇的青石板路}}}}",
-                        "url": "https://cos.example.com/0.png",
+                        "url": "https://life-echo-dev-1319381411.cos.ap-shanghai.myqcloud.com/memoirs/u1/c1/0.png",
+                        "storage_key": "memoirs/u1/c1/0.png",
                         "status": "completed",
                     }
                 ],
@@ -44,3 +53,4 @@ class PDFServiceImagesTest(unittest.IsolatedAsyncioTestCase):
 
         self.assertGreater(len(pdf_bytes), 100)
         self.assertNotIn(b"IMAGE:", pdf_bytes)
+        mock_client.get.assert_called_once_with("https://signed.example.com/0.png?sig=123")
diff --git a/api/tests/test_process_memoir_segments_image_enqueue.py b/api/tests/test_process_memoir_segments_image_enqueue.py
index f6b5de8..0e17efe 100644
--- a/api/tests/test_process_memoir_segments_image_enqueue.py
+++ b/api/tests/test_process_memoir_segments_image_enqueue.py
@@ -35,6 +35,7 @@ class ProcessMemoirSegmentsImageEnqueueTest(unittest.TestCase):
             default_size="1024x1024",
             poll_interval_seconds=3,
             max_attempts=20,
+            liblib_template_uuid="tpl-uuid",
         )
         get_state_mock.return_value = SimpleNamespace(current_stage="childhood", slots={})
 
diff --git a/app-android/app/src/main/java/com/huaga/life_echo/ui/components/memoir/MemoirContentBlocks.kt b/app-android/app/src/main/java/com/huaga/life_echo/ui/components/memoir/MemoirContentBlocks.kt
index 4a0b6fe..17746bd 100644
--- a/app-android/app/src/main/java/com/huaga/life_echo/ui/components/memoir/MemoirContentBlocks.kt
+++ b/app-android/app/src/main/java/com/huaga/life_echo/ui/components/memoir/MemoirContentBlocks.kt
@@ -18,7 +18,9 @@ fun splitMemoirContent(content: String, images: List<ChapterImageDto>): List<Mem
     val blocks = mutableListOf<MemoirContentBlock>()
     images.sortedBy { it.index }.forEach { image ->
         val placeholder = image.placeholder
-        if (!remaining.contains(placeholder)) return@forEach
+        if (!remaining.contains(placeholder)) {
+            return@forEach
+        }
         val parts = remaining.split(placeholder, limit = 2)
         val before = stripImagePlaceholders(parts.first())
         if (before.isNotBlank()) blocks += MemoirContentBlock.Text(before)
diff --git a/app-android/app/src/main/java/com/huaga/life_echo/ui/components/memoir/MemoirInlineImage.kt b/app-android/app/src/main/java/com/huaga/life_echo/ui/components/memoir/MemoirInlineImage.kt
index 015bb0b..9eb60c3 100644
--- a/app-android/app/src/main/java/com/huaga/life_echo/ui/components/memoir/MemoirInlineImage.kt
+++ b/app-android/app/src/main/java/com/huaga/life_echo/ui/components/memoir/MemoirInlineImage.kt
@@ -8,8 +8,8 @@ import androidx.compose.animation.core.tween
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.aspectRatio
 import androidx.compose.foundation.layout.fillMaxWidth
-import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
@@ -20,12 +20,53 @@ import androidx.compose.ui.draw.clip
 import androidx.compose.ui.layout.ContentScale
 import androidx.compose.ui.platform.testTag
 import androidx.compose.ui.unit.dp
-import coil.compose.AsyncImage
+import coil.compose.SubcomposeAsyncImage
 import com.huaga.life_echo.network.models.ChapterImageDto
 import com.huaga.life_echo.ui.theme.AppTypography
 import com.huaga.life_echo.ui.theme.LightPurple
 import com.huaga.life_echo.ui.theme.SlatePurple
 
+internal fun memoirImageAspectRatio(size: String?): Float {
+    val match = Regex("""^\s*(\d+)\s*x\s*(\d+)\s*$""").matchEntire(size.orEmpty()) ?: return 1f
+    val width = match.groupValues[1].toFloatOrNull() ?: return 1f
+    val height = match.groupValues[2].toFloatOrNull() ?: return 1f
+    if (width <= 0f || height <= 0f) return 1f
+    return width / height
+}
+
+@Composable
+private fun MemoirImageLoadingPlaceholder(
+    image: ChapterImageDto,
+    modifier: Modifier = Modifier,
+    text: String = "图片生成中…",
+) {
+    val transition = rememberInfiniteTransition(label = "shimmer")
+    val alpha by transition.animateFloat(
+        initialValue = 0.10f,
+        targetValue = 0.25f,
+        animationSpec = infiniteRepeatable(
+            animation = tween(800),
+            repeatMode = RepeatMode.Reverse
+        ),
+        label = "shimmer-alpha"
+    )
+    Box(
+        modifier = modifier
+            .fillMaxWidth()
+            .aspectRatio(memoirImageAspectRatio(image.size))
+            .clip(RoundedCornerShape(16.dp))
+            .background(LightPurple.copy(alpha = alpha))
+            .testTag("memoir-image-loading-${image.index}"),
+        contentAlignment = Alignment.Center,
+    ) {
+        Text(
+            text = text,
+            fontSize = AppTypography.bodyMedium,
+            color = SlatePurple.copy(alpha = 0.6f),
+        )
+    }
+}
+
 @Composable
 fun MemoirInlineImage(
     image: ChapterImageDto,
@@ -33,43 +74,36 @@ fun MemoirInlineImage(
     modifier: Modifier = Modifier,
 ) {
     when (image.status) {
-        "completed" -> AsyncImage(
+        "completed" -> SubcomposeAsyncImage(
             model = image.url,
             contentDescription = image.description,
             contentScale = ContentScale.FillWidth,
+            loading = {
+                MemoirImageLoadingPlaceholder(
+                    image = image,
+                    modifier = modifier,
+                    text = "图片加载中…",
+                )
+            },
+            error = {
+                MemoirImageLoadingPlaceholder(
+                    image = image,
+                    modifier = modifier,
+                    text = "图片暂不可用",
+                )
+            },
             modifier = modifier
                 .fillMaxWidth()
+                .aspectRatio(memoirImageAspectRatio(image.size))
                 .clip(RoundedCornerShape(16.dp))
                 .clickable(onClick = onClick)
                 .testTag("memoir-image-${image.index}")
         )
-        "pending", "processing" -> {
-            val transition = rememberInfiniteTransition(label = "shimmer")
-            val alpha by transition.animateFloat(
-                initialValue = 0.10f,
-                targetValue = 0.25f,
-                animationSpec = infiniteRepeatable(
-                    animation = tween(800),
-                    repeatMode = RepeatMode.Reverse
-                ),
-                label = "shimmer-alpha"
-            )
-            Box(
-                modifier = modifier
-                    .fillMaxWidth()
-                    .height(220.dp)
-                    .clip(RoundedCornerShape(16.dp))
-                    .background(LightPurple.copy(alpha = alpha))
-                    .testTag("memoir-image-loading-${image.index}"),
-                contentAlignment = Alignment.Center,
-            ) {
-                Text(
-                    text = "图片生成中…",
-                    fontSize = AppTypography.bodyMedium,
-                    color = SlatePurple.copy(alpha = 0.6f),
-                )
-            }
-        }
+        "pending", "processing" -> MemoirImageLoadingPlaceholder(
+            image = image,
+            modifier = modifier,
+            text = "图片生成中…",
+        )
         else -> Unit
     }
 }
diff --git a/app-android/app/src/main/java/com/huaga/life_echo/ui/screens/MemoirImagePolling.kt b/app-android/app/src/main/java/com/huaga/life_echo/ui/screens/MemoirImagePolling.kt
new file mode 100644
index 0000000..2fad380
--- /dev/null
+++ b/app-android/app/src/main/java/com/huaga/life_echo/ui/screens/MemoirImagePolling.kt
@@ -0,0 +1,13 @@
+package com.huaga.life_echo.ui.screens
+
+import com.huaga.life_echo.network.models.ChapterDto
+
+internal const val MEMOIR_IMAGE_POLL_INTERVAL_MS = 3_000L
+
+internal fun hasPendingMemoirImages(chapters: List<ChapterDto>): Boolean {
+    return chapters.any { chapter ->
+        chapter.images.any { image ->
+            image.status == "pending" || image.status == "processing"
+        }
+    }
+}
diff --git a/app-android/app/src/main/java/com/huaga/life_echo/ui/screens/MyMemoirScreen.kt b/app-android/app/src/main/java/com/huaga/life_echo/ui/screens/MyMemoirScreen.kt
index 12dc788..3b2dd0c 100644
--- a/app-android/app/src/main/java/com/huaga/life_echo/ui/screens/MyMemoirScreen.kt
+++ b/app-android/app/src/main/java/com/huaga/life_echo/ui/screens/MyMemoirScreen.kt
@@ -35,6 +35,7 @@ import com.huaga.life_echo.ui.settings.AppSettings
 import com.huaga.life_echo.ui.theme.*
 import com.huaga.life_echo.ui.viewmodel.MyMemoirViewModel
 import com.huaga.life_echo.ui.viewmodel.ViewModelFactory
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.launch
 
 /**
@@ -164,6 +165,22 @@ fun MyMemoirScreen(
     val contentChapters = remember(chapterDtos) {
         chapterDtos.filter { it.content.isNotBlank() }
     }
+    val shouldPollChapterImages = remember(chapterDtos) {
+        hasPendingMemoirImages(chapterDtos)
+    }
+    val latestIsLoading by rememberUpdatedState(isLoading)
+    val latestIsRefreshing by rememberUpdatedState(isRefreshing)
+
+    LaunchedEffect(shouldPollChapterImages) {
+        if (!shouldPollChapterImages) return@LaunchedEffect
+
+        while (true) {
+            delay(MEMOIR_IMAGE_POLL_INTERVAL_MS)
+            if (!latestIsLoading && !latestIsRefreshing) {
+                viewModel.refreshChapters()
+            }
+        }
+    }
     
     AnimatedContent(
         targetState = showFullTextReading || selectedChapter != null,
diff --git a/app-android/app/src/main/java/com/huaga/life_echo/ui/viewmodel/MyMemoirViewModel.kt b/app-android/app/src/main/java/com/huaga/life_echo/ui/viewmodel/MyMemoirViewModel.kt
index a1023cc..b4c9e76 100644
--- a/app-android/app/src/main/java/com/huaga/life_echo/ui/viewmodel/MyMemoirViewModel.kt
+++ b/app-android/app/src/main/java/com/huaga/life_echo/ui/viewmodel/MyMemoirViewModel.kt
@@ -205,4 +205,3 @@ class MyMemoirViewModel(
         }
     }
 }
-
diff --git a/app-android/app/src/test/java/com/huaga/life_echo/ui/components/chat/ChatInputPresentationTest.kt b/app-android/app/src/test/java/com/huaga/life_echo/ui/components/chat/ChatInputPresentationTest.kt
index 1e698c5..b347ad4 100644
--- a/app-android/app/src/test/java/com/huaga/life_echo/ui/components/chat/ChatInputPresentationTest.kt
+++ b/app-android/app/src/test/java/com/huaga/life_echo/ui/components/chat/ChatInputPresentationTest.kt
@@ -38,7 +38,6 @@ class ChatInputPresentationTest {
         )
 
         assertEquals(ChatInputLeadingAction.SWITCH_TO_VOICE, presentation.leadingAction)
-        assertTrue(presentation.showEmojiAction)
         assertEquals(ChatInputTrailingAction.ADD, presentation.trailingAction)
     }
 
@@ -51,7 +50,6 @@ class ChatInputPresentationTest {
         )
 
         assertEquals(ChatInputTrailingAction.SEND, presentation.trailingAction)
-        assertTrue(presentation.showEmojiAction)
     }
 
     @Test
@@ -63,7 +61,6 @@ class ChatInputPresentationTest {
         )
 
         assertEquals(ChatInputLeadingAction.SWITCH_TO_TEXT, presentation.leadingAction)
-        assertTrue(presentation.showEmojiAction)
         assertEquals(ChatInputTrailingAction.ADD, presentation.trailingAction)
     }
 
@@ -76,7 +73,6 @@ class ChatInputPresentationTest {
         )
 
         assertEquals(ChatInputLeadingAction.SWITCH_TO_TEXT, presentation.leadingAction)
-        assertFalse(presentation.showEmojiAction)
         assertEquals(ChatInputTrailingAction.CANCEL, presentation.trailingAction)
     }
 
diff --git a/app-android/app/src/test/java/com/huaga/life_echo/ui/components/memoir/MemoirInlineImageSizingTest.kt b/app-android/app/src/test/java/com/huaga/life_echo/ui/components/memoir/MemoirInlineImageSizingTest.kt
new file mode 100644
index 0000000..e2db6a2
--- /dev/null
+++ b/app-android/app/src/test/java/com/huaga/life_echo/ui/components/memoir/MemoirInlineImageSizingTest.kt
@@ -0,0 +1,30 @@
+package com.huaga.life_echo.ui.components.memoir
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class MemoirInlineImageSizingTest {
+
+    @Test
+    fun memoirImageAspectRatio_defaultsToSquare_whenSizeMissing() {
+        assertEquals(1f, memoirImageAspectRatio(null), 0.0001f)
+        assertEquals(1f, memoirImageAspectRatio(""), 0.0001f)
+    }
+
+    @Test
+    fun memoirImageAspectRatio_parsesSquareSize() {
+        assertEquals(1f, memoirImageAspectRatio("1024x1024"), 0.0001f)
+    }
+
+    @Test
+    fun memoirImageAspectRatio_parsesLandscapeAndPortraitSizes() {
+        assertEquals(1.5f, memoirImageAspectRatio("1536x1024"), 0.0001f)
+        assertEquals(0.6667f, memoirImageAspectRatio("1024x1536"), 0.0001f)
+    }
+
+    @Test
+    fun memoirImageAspectRatio_fallsBackToSquare_whenSizeMalformed() {
+        assertEquals(1f, memoirImageAspectRatio("oops"), 0.0001f)
+        assertEquals(1f, memoirImageAspectRatio("1024x0"), 0.0001f)
+    }
+}
diff --git a/app-android/app/src/test/java/com/huaga/life_echo/ui/screens/MemoirImagePollingTest.kt b/app-android/app/src/test/java/com/huaga/life_echo/ui/screens/MemoirImagePollingTest.kt
new file mode 100644
index 0000000..eb7a53b
--- /dev/null
+++ b/app-android/app/src/test/java/com/huaga/life_echo/ui/screens/MemoirImagePollingTest.kt
@@ -0,0 +1,60 @@
+package com.huaga.life_echo.ui.screens
+
+import com.huaga.life_echo.network.models.ChapterDto
+import com.huaga.life_echo.network.models.ChapterImageDto
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+class MemoirImagePollingTest {
+
+    @Test
+    fun hasPendingMemoirImages_returnsTrue_whenAnyImageIsPendingOrProcessing() {
+        val chapters = listOf(
+            chapterWithImages("completed"),
+            chapterWithImages("processing"),
+        )
+
+        assertTrue(hasPendingMemoirImages(chapters))
+    }
+
+    @Test
+    fun hasPendingMemoirImages_returnsFalse_whenAllImagesAreTerminal() {
+        val chapters = listOf(
+            chapterWithImages("completed"),
+            chapterWithImages("failed"),
+        )
+
+        assertFalse(hasPendingMemoirImages(chapters))
+    }
+
+    private fun chapterWithImages(status: String): ChapterDto {
+        return ChapterDto(
+            id = "chapter-$status",
+            title = "title-$status",
+            content = "content-$status",
+            order_index = 0,
+            status = "partial",
+            category = "childhood",
+            images = listOf(
+                ChapterImageDto(
+                    index = 0,
+                    placeholder = "{{IMAGE:$status}}",
+                    description = status,
+                    prompt = null,
+                    url = if (status == "completed") "https://cos.example.com/$status.png" else null,
+                    status = status,
+                    provider = "liblib",
+                    style = "memoir",
+                    size = "1024x1024",
+                    error = null,
+                    created_at = null,
+                    updated_at = null,
+                )
+            ),
+            updated_at = null,
+            is_new = false,
+            source_segments = emptyList(),
+        )
+    }
+}