diff --git a/backend/Dockerfile b/backend/Dockerfile
index 33a57a9..2bbc64a 100644
--- a/backend/Dockerfile
+++ b/backend/Dockerfile
@@ -1,6 +1,9 @@
 FROM python:3.12-slim
 
-RUN apt-get update && apt-get install -y --no-install-recommends \
+ARG APT_MIRROR=mirrors.tuna.tsinghua.edu.cn
+RUN sed -i "s|deb.debian.org|${APT_MIRROR}|g; s|security.debian.org|${APT_MIRROR}|g" \
+      /etc/apt/sources.list /etc/apt/sources.list.d/*.sources 2>/dev/null || true \
+    && apt-get update && apt-get install -y --no-install-recommends \
     fping iputils-ping && \
     rm -rf /var/lib/apt/lists/*