diff --git a/infra/docker/worker.Dockerfile b/infra/docker/worker.Dockerfile
index 26f20d807..d7549fb28 100755
--- a/infra/docker/worker.Dockerfile
+++ b/infra/docker/worker.Dockerfile
@@ -25,17 +25,44 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     xz-utils \
     && rm -rf /var/lib/apt/lists/*
 
-# ---- 下载静态编译 ffmpeg（带缓存，避免每次重新下载）----
+# ---- 下载静态编译 ffmpeg（带缓存+完整性校验+多源重试）----
+# 问题背景：johnvansickle.com 偶尔返回损坏文件，缓存命中坏包后反复失败
+# 修复策略：1.三源下载 2.tar完整性校验 3.损坏删缓存重试 4.二进制可执行校验
 RUN --mount=type=cache,target=/tmp/ffmpeg-cache,sharing=locked \
     cd /tmp \
-    && if [ ! -f /tmp/ffmpeg-cache/ffmpeg-release-amd64-static.tar.xz ]; then \
-         wget -q -O /tmp/ffmpeg-cache/ffmpeg-release-amd64-static.tar.xz \
-           https://johnvansickle.com/ffmpeg/releases/ffmpeg-release-amd64-static.tar.xz; \
-       fi \
-    && tar xf /tmp/ffmpeg-cache/ffmpeg-release-amd64-static.tar.xz \
+    && FFMPEG_FILE="/tmp/ffmpeg-cache/ffmpeg-release-amd64-static.tar.xz" \
+    && FFMPEG_SOURCES=( \
+         "https://johnvansickle.com/ffmpeg/releases/ffmpeg-release-amd64-static.tar.xz" \
+         "https://mirrors.tuna.tsinghua.edu.cn/ffmpeg/releases/ffmpeg-release-amd64-static.tar.xz" \
+         "https://mirrors.ustc.edu.cn/ffmpeg/releases/ffmpeg-release-amd64-static.tar.xz" \
+       ) \
+    && download_ok=0 \
+    && for src in "${FFMPEG_SOURCES[@]}"; do \
+         if [ $download_ok -eq 0 ] && [ -f "$FFMPEG_FILE" ] && tar -tf "$FFMPEG_FILE" >/dev/null 2>&1; then \
+           echo "[ffmpeg] cache valid, skip download"; \
+           download_ok=1; \
+           break; \
+         fi; \
+         rm -f "$FFMPEG_FILE"; \
+         echo "[ffmpeg] downloading from $src"; \
+         if wget -q --tries=3 --timeout=30 -O "$FFMPEG_FILE" "$src"; then \
+           if tar -tf "$FFMPEG_FILE" >/dev/null 2>&1; then \
+             echo "[ffmpeg] download OK, tar valid"; \
+             download_ok=1; \
+             break; \
+           else \
+             echo "[ffmpeg] corrupted file, removing cache"; \
+             rm -f "$FFMPEG_FILE"; \
+           fi; \
+         fi; \
+       done \
+    && if [ $download_ok -eq 0 ]; then echo "[ffmpeg] ALL SOURCES FAILED"; exit 1; fi \
+    && tar xf "$FFMPEG_FILE" \
     && cp ffmpeg-*-amd64-static/ffmpeg /usr/local/bin/ffmpeg \
     && cp ffmpeg-*-amd64-static/ffprobe /usr/local/bin/ffprobe \
     && chmod +x /usr/local/bin/ffmpeg /usr/local/bin/ffprobe \
+    && ffmpeg -version >/dev/null 2>&1 && ffprobe -version >/dev/null 2>&1 \
+    && echo "[ffmpeg] binary valid" \
     && rm -rf ffmpeg-*
 
 # ---- 安装 Python 依赖 ----