diff --git a/deploy/Dockerfile b/deploy/Dockerfile
index 8a7b6cff..3efe271f 100644
--- a/deploy/Dockerfile
+++ b/deploy/Dockerfile
@@ -45,8 +45,17 @@ WORKDIR /build
 
 COPY composer.json composer.lock ./
 
+## 可选：Composer 下载源（留空使用官方源）。
+## 国内网络访问 GitHub 受限时，发布脚本会传入镜像源，例如 https://mirrors.cloud.tencent.com/composer/。
+ARG COMPOSER_REPO_PACKAGIST=""
+
 RUN --mount=type=cache,target=/tmp/composer-cache \
     set -eu; \
+    if [ -n "${COMPOSER_REPO_PACKAGIST:-}" ]; then \
+        export COMPOSER_REPO_PACKAGIST; \
+    else \
+        unset COMPOSER_REPO_PACKAGIST; \
+    fi; \
     attempt=1; \
     while true; do \
         if COMPOSER_CACHE_DIR=/tmp/composer-cache \
diff --git a/scripts/deploy-from-mac.sh b/scripts/deploy-from-mac.sh
index dcf69ef0..c1a5d29d 100755
--- a/scripts/deploy-from-mac.sh
+++ b/scripts/deploy-from-mac.sh
@@ -21,6 +21,10 @@
 #   --keep-images <数量>      默认 2
 #   --app-version <版本>      默认 3.1.15
 #
+# 环境变量：CAIWU_COMPOSER_REPO_PACKAGIST 可覆盖 Composer 下载源
+#   （默认 https://mirrors.cloud.tencent.com/composer/；国内网络访问 GitHub 受限时使用，
+#    设为空字符串则使用 Composer 官方源）
+#
 set -euo pipefail
 
 server='218.93.190.75'
@@ -43,6 +47,8 @@ allow_non_main=0
 allow_migrations=0
 skip_regctl=0
 app_version='3.1.15'
+# 国内网络访问 GitHub 受限时，composer 的 GitHub dist 会失败；默认走腾讯云镜像。
+composer_repo_packagist="${CAIWU_COMPOSER_REPO_PACKAGIST-https://mirrors.cloud.tencent.com/composer/}"
 
 while [ "$#" -gt 0 ]; do
     case "$1" in
@@ -469,6 +475,7 @@ build_image() {
         --build-arg "VCS_REF=$deploy_sha" \
         --build-arg "BUILD_DATE=$build_date" \
         --build-arg "APP_VERSION=$app_version" \
+        --build-arg "COMPOSER_REPO_PACKAGIST=$composer_repo_packagist" \
         --label 'com.caiwu.project=CaiWuXiTong' \
         --file deploy/Dockerfile \
         .
@@ -577,6 +584,7 @@ else
         --build-arg "VCS_REF=$deploy_sha" \
         --build-arg "BUILD_DATE=$build_date" \
         --build-arg "APP_VERSION=$app_version" \
+        --build-arg "COMPOSER_REPO_PACKAGIST=$composer_repo_packagist" \
         --label 'com.caiwu.project=CaiWuXiTong' \
         --file deploy/Dockerfile \
         . || fail '导出稳定分层的 OCI 应用镜像失败。'