diff --git a/fish_api/README.md b/fish_api/README.md
index 2e6dc49..03e9b56 100644
--- a/fish_api/README.md
+++ b/fish_api/README.md
@@ -97,6 +97,27 @@ FishMeasure 跑完后在输出目录查找 `*preview*.mp4`，复制到 `MEDIA_RO
 
 DGCNN 明细中同时输出 `mean_all_pred_g_after_filters`、`avg_topk_mean_pred_g` 等供对比参考。
 
+## Debug：单条鱼测量（与 fish_api 同逻辑）
+
+不启动 uvicorn、**不写 SQLite**、**不发布** `MEDIA_ROOT`（与 `run_full_measure_batch` 相比仅少快照与媒体发布；FishMeasure 子进程与 `measure_output/fish{N}` 与线上一致）。
+
+调用 [`app/services/measure.py`](app/services/measure.py) 中的 `run_measure_batch_subprocess`，配置与 `fish_api/.env` 相同（`get_settings()`）。
+
+```bash
+cd fish_api
+uv sync
+# 默认：MEASURE_WATCH_DIR/fish{N}/ 下所有 .svo2 → 输出到 MEASURE_OUTPUT_ROOT/fish{N}（默认 fish_api/.data/measure_output/fish{N}）
+uv run python -m app.measure_debug_cli --fish-id 1
+
+# 或等价入口
+uv run fish-measure-debug --fish-id 1
+
+# 指定 SVO 目录或输出目录
+uv run python -m app.measure_debug_cli --batch-folder /path/to/fish1 --fish-id 1 --output-root /path/to/out
+```
+
+结束后会在终端打印 `weight_prediction.json` 中的 `pred_weight_g`、`pred_weight_rule` 等摘要。
+
 ## 演进建议
 
 - RTSP：用 `ffmpeg` 切段写入 MP4 后调用现有 `finalize` 逻辑
diff --git a/fish_api/app/measure_debug_cli.py b/fish_api/app/measure_debug_cli.py
new file mode 100644
index 0000000..ba703ac
--- /dev/null
+++ b/fish_api/app/measure_debug_cli.py
@@ -0,0 +1,127 @@
+"""CLI：对单条 fish 跑与 fish_api / measure-watch 相同的 FishMeasure 子进程（不写 SQLite、不发布 /media）。
+
+使用 ``run_measure_batch_subprocess``，与 ``run_full_measure_batch`` 中的推理步骤一致。
+"""
+
+from __future__ import annotations
+
+import argparse
+import json
+import sys
+from pathlib import Path
+from typing import Any, Dict, List
+
+from app.services.measure import run_measure_batch_subprocess
+from app.settings import get_settings
+
+
+def _sorted_svo2_in_folder(folder: Path) -> List[Path]:
+    """与 measure_watch.iter_svo2_folders 中单目录内 .svo2 列表一致（按文件名排序）。"""
+    return sorted(
+        [p for p in folder.iterdir() if p.is_file() and p.suffix.lower() == ".svo2"],
+        key=lambda p: p.name,
+    )
+
+
+def _print_weight_summary(output_root: Path) -> None:
+    combined = output_root / "weight_prediction.json"
+    if not combined.is_file():
+        print(f"[measure-debug] no combined file: {combined}", file=sys.stderr)
+        return
+    try:
+        with open(combined, encoding="utf-8") as f:
+            data: Dict[str, Any] = json.load(f)
+    except (OSError, json.JSONDecodeError) as e:
+        print(f"[measure-debug] failed to read {combined}: {e}", file=sys.stderr)
+        return
+
+    summary = data.get("dgcnn_summary") or data.get("weight_summary") or {}
+    pred_g = data.get("pred_weight_g")
+    rule = data.get("pred_weight_rule")
+    print("[measure-debug] --- weight_prediction.json (summary) ---")
+    if pred_g is not None:
+        print(f"  pred_weight_g: {pred_g}")
+    if rule is not None:
+        print(f"  pred_weight_rule: {rule}")
+    if summary:
+        top_k = summary.get("top_k")
+        tbl = summary.get("top_by_length")
+        print(f"  dgcnn_summary.top_k: {top_k}")
+        print(f"  dgcnn_summary.top_by_length: {tbl}")
+    mean_all = data.get("mean_all_pred_g_after_filters")
+    if mean_all is not None:
+        print(f"  mean_all_pred_g_after_filters: {mean_all}")
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(
+        description="Run FishMeasure for one fish folder (same subprocess as fish_api)."
+    )
+    parser.add_argument(
+        "--fish-id",
+        default="1",
+        help='Fish id used for output dir measure_output/fish{N} (default: 1).',
+    )
+    parser.add_argument(
+        "--batch-folder",
+        type=Path,
+        default=None,
+        help="Folder containing .svo2 files (overrides MEASURE_WATCH_DIR/fish{N}).",
+    )
+    parser.add_argument(
+        "--watch-dir",
+        type=Path,
+        default=None,
+        help="Override MEASURE_WATCH_DIR when resolving fish{N}/ (ignored if --batch-folder is set).",
+    )
+    parser.add_argument(
+        "--output-root",
+        type=Path,
+        default=None,
+        help="Override save-output directory (default: MEASURE_OUTPUT_ROOT/fish{N}).",
+    )
+    args = parser.parse_args()
+
+    settings = get_settings()
+    fish_id = str(args.fish_id).strip() or "1"
+
+    if args.batch_folder is not None:
+        batch_folder = args.batch_folder.expanduser().resolve()
+    else:
+        watch = args.watch_dir if args.watch_dir is not None else settings.measure_watch_dir
+        if watch is None:
+            print(
+                "未配置输入目录：请设置 --batch-folder，或在 .env 中设置 MEASURE_WATCH_DIR",
+                file=sys.stderr,
+            )
+            raise SystemExit(2)
+        watch = watch.expanduser().resolve()
+        batch_folder = watch / f"fish{fish_id}"
+
+    if not batch_folder.is_dir():
+        print(f"不是目录或不存在: {batch_folder}", file=sys.stderr)
+        raise SystemExit(2)
+
+    svo_paths = _sorted_svo2_in_folder(batch_folder)
+    if not svo_paths:
+        print(f"目录下无 .svo2 文件: {batch_folder}", file=sys.stderr)
+        raise SystemExit(2)
+
+    if args.output_root is not None:
+        out_root = args.output_root.expanduser().resolve()
+    else:
+        out_root = settings.measure_output_root / f"fish{fish_id}"
+    out_root.mkdir(parents=True, exist_ok=True)
+
+    print(f"[measure-debug] batch_folder={batch_folder}")
+    print(f"[measure-debug] output_root={out_root}")
+    print(f"[measure-debug] {len(svo_paths)} SVO(s): {', '.join(p.name for p in svo_paths)}")
+
+    run_measure_batch_subprocess(svo_paths, settings, output_root=out_root)
+
+    _print_weight_summary(out_root)
+    print("[measure-debug] done.")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/fish_api/pyproject.toml b/fish_api/pyproject.toml
index 68f0c76..85d19a2 100644
--- a/fish_api/pyproject.toml
+++ b/fish_api/pyproject.toml
@@ -16,3 +16,4 @@ dev = ["httpx>=0.28.1"]
 
 [project.scripts]
 fish-action-watch = "app.action_watch_cli:main"
+fish-measure-debug = "app.measure_debug_cli:main"