diff --git a/backend/app/access_log_filters.py b/backend/app/access_log_filters.py
index 2a302fd..8592ecf 100644
--- a/backend/app/access_log_filters.py
+++ b/backend/app/access_log_filters.py
@@ -8,10 +8,13 @@ import logging
 def should_log_uvicorn_access_line(message: str) -> bool:
     """Return False to suppress a uvicorn access log line."""
     msg = message or ""
-    if "GET" in msg and " 200 " in msg and "/health" in msg:
+    if "GET" in msg and '" 200' in msg and "/health" in msg:
         return False
     if "GET" in msg and " 404 " in msg and "/pending-confirmation" in msg:
         return False
+    # HLS 预览反代：m3u8 / fMP4 分片轮询，成功 200 为常态噪声
+    if "GET" in msg and '" 200' in msg and "/internal/demo/hls-preview/" in msg:
+        return False
     return True
 
 
diff --git a/backend/tests/test_access_log_filters.py b/backend/tests/test_access_log_filters.py
index ea23c60..fcf0a82 100644
--- a/backend/tests/test_access_log_filters.py
+++ b/backend/tests/test_access_log_filters.py
@@ -28,3 +28,26 @@ def test_keep_pending_200() -> None:
 def test_keep_start_post() -> None:
     line = '192.168.3.85:9999 - "POST /client/surgeries/start HTTP/1.1" 503 Service Unavailable'
     assert should_log_uvicorn_access_line(line) is True
+
+
+def test_suppress_hls_preview_m3u8_200() -> None:
+    line = (
+        '172.21.0.1:40496 - "GET /internal/demo/hls-preview/or-cam-02/video1_stream.m3u8'
+        '?session=b7faf66b&_HLS_msn=17&_HLS_part=2&_HLS_skip=YES HTTP/1.1" 200'
+    )
+    assert should_log_uvicorn_access_line(line) is False
+
+
+def test_suppress_hls_preview_mp4_200() -> None:
+    line = (
+        '172.21.0.1:40472 - "GET /internal/demo/hls-preview/or-cam-02/'
+        '0e238a860dec_video1_part102.mp4?session=b7faf66b HTTP/1.1" 200'
+    )
+    assert should_log_uvicorn_access_line(line) is False
+
+
+def test_keep_hls_preview_404() -> None:
+    line = (
+        '172.21.0.1:40472 - "GET /internal/demo/hls-preview/or-cam-02/index.m3u8 HTTP/1.1" 404'
+    )
+    assert should_log_uvicorn_access_line(line) is True