diff --git a/docs/help/testing.md b/docs/help/testing.md
index 32818e20239..09dc34da1b6 100644
--- a/docs/help/testing.md
+++ b/docs/help/testing.md
@@ -976,6 +976,7 @@ The live-model Docker runners also bind-mount only the needed CLI auth homes (or
 - Onboarding wizard (TTY, full scaffolding): `pnpm test:docker:onboard` (script: `scripts/e2e/onboard-docker.sh`)
 - Npm tarball onboarding/channel/agent smoke: `pnpm test:docker:npm-onboard-channel-agent` installs the packed OpenClaw tarball globally in Docker, configures OpenAI via env-ref onboarding plus Telegram by default, verifies enabling the plugin installs its runtime deps on demand, runs doctor, and runs one mocked OpenAI agent turn. Reuse a prebuilt tarball with `OPENCLAW_NPM_ONBOARD_PACKAGE_TGZ=/path/to/openclaw-*.tgz`, skip the host rebuild with `OPENCLAW_NPM_ONBOARD_HOST_BUILD=0`, or switch channel with `OPENCLAW_NPM_ONBOARD_CHANNEL=discord`.
 - Bun global install smoke: `bash scripts/e2e/bun-global-install-smoke.sh` packs the current tree, installs it with `bun install -g` in an isolated home, and verifies `openclaw infer image providers --json` returns bundled image providers instead of hanging. Reuse a prebuilt tarball with `OPENCLAW_BUN_GLOBAL_SMOKE_PACKAGE_TGZ=/path/to/openclaw-*.tgz`, skip the host build with `OPENCLAW_BUN_GLOBAL_SMOKE_HOST_BUILD=0`, or copy `dist/` from a built Docker image with `OPENCLAW_BUN_GLOBAL_SMOKE_DIST_IMAGE=openclaw-dockerfile-smoke:local`.
+- Installer Docker smoke: `bash scripts/test-install-sh-docker.sh` shares one npm cache across its root, update, direct-npm, and non-root containers. Set `OPENCLAW_INSTALL_SMOKE_NPM_CACHE_DIR=/path/to/cache` to reuse that cache across local reruns.
 - Gateway networking (two containers, WS auth + health): `pnpm test:docker:gateway-network` (script: `scripts/e2e/gateway-network-docker.sh`)
 - OpenAI Responses web_search minimal reasoning regression: `pnpm test:docker:openai-web-search-minimal` (script: `scripts/e2e/openai-web-search-minimal-docker.sh`) runs a mocked OpenAI server through Gateway, verifies `web_search` raises `reasoning.effort` from `minimal` to `low`, then forces the provider schema reject and checks the raw detail appears in Gateway logs.
 - MCP channel bridge (seeded Gateway + stdio bridge + raw Claude notification-frame smoke): `pnpm test:docker:mcp-channels` (script: `scripts/e2e/mcp-channels-docker.sh`)
diff --git a/scripts/test-install-sh-docker.sh b/scripts/test-install-sh-docker.sh
index d94cc3edb95..4dcd6d35b6b 100755
--- a/scripts/test-install-sh-docker.sh
+++ b/scripts/test-install-sh-docker.sh
@@ -166,12 +166,18 @@ BASELINE_TAG_URL=""
 FRESH_TAG_URL=""
 UPDATE_TAG_URL=""
 UPDATE_DOCKER_HOST_ARGS=()
+NPM_CACHE_DIR="${OPENCLAW_INSTALL_SMOKE_NPM_CACHE_DIR:-}"
+NPM_CACHE_OWNED=0
+NPM_CACHE_DOCKER_ARGS=()
 
 cleanup() {
   if [[ -n "$UPDATE_SERVER_PID" ]]; then
     kill "$UPDATE_SERVER_PID" >/dev/null 2>&1 || true
     wait "$UPDATE_SERVER_PID" >/dev/null 2>&1 || true
   fi
+  if [[ "$NPM_CACHE_OWNED" == "1" && -n "$NPM_CACHE_DIR" ]]; then
+    rm -rf "$NPM_CACHE_DIR"
+  fi
   rm -rf "$LATEST_DIR" "$UPDATE_DIR"
 }
 
@@ -288,6 +294,20 @@ prepare_update_host_access() {
   fi
 }
 
+prepare_npm_cache() {
+  if [[ -z "$NPM_CACHE_DIR" ]]; then
+    NPM_CACHE_DIR="$(mktemp -d)"
+    NPM_CACHE_OWNED=1
+  fi
+  mkdir -p "$NPM_CACHE_DIR"
+  chmod 0777 "$NPM_CACHE_DIR"
+  NPM_CACHE_DOCKER_ARGS=(
+    -v "${NPM_CACHE_DIR}:/npm-cache"
+    -e npm_config_cache=/npm-cache
+    -e NPM_CONFIG_CACHE=/npm-cache
+  )
+}
+
 start_update_server() {
   if [[ -z "$UPDATE_PORT" ]]; then
     UPDATE_PORT="$(allocate_host_port)"
@@ -326,12 +346,14 @@ if [[ "$SKIP_UPDATE" == "1" ]]; then
 else
   prepare_update_tarball
   prepare_update_host_access
+  prepare_npm_cache
   start_update_server
 
   echo "==> Run installer smoke test (root): $FRESH_TAG_URL"
   docker run --rm -t \
     --platform "$SMOKE_PLATFORM" \
     ${UPDATE_DOCKER_HOST_ARGS[@]+"${UPDATE_DOCKER_HOST_ARGS[@]}"} \
+    "${NPM_CACHE_DOCKER_ARGS[@]}" \
     -v "${LATEST_DIR}:/out" \
     -e OPENCLAW_INSTALL_URL="$INSTALL_URL" \
     -e OPENCLAW_INSTALL_PACKAGE="$PACKAGE_NAME" \
@@ -353,6 +375,7 @@ else
   docker run --rm -t \
     --platform "$SMOKE_PLATFORM" \
     ${UPDATE_DOCKER_HOST_ARGS[@]+"${UPDATE_DOCKER_HOST_ARGS[@]}"} \
+    "${NPM_CACHE_DOCKER_ARGS[@]}" \
     -e OPENCLAW_INSTALL_PACKAGE="$PACKAGE_NAME" \
     -e OPENCLAW_INSTALL_SMOKE_MODE=update \
     -e OPENCLAW_INSTALL_UPDATE_BASELINE="$UPDATE_BASELINE_VERSION" \
@@ -371,6 +394,7 @@ else
     docker run --rm -t \
       --platform "$SMOKE_PLATFORM" \
       ${UPDATE_DOCKER_HOST_ARGS[@]+"${UPDATE_DOCKER_HOST_ARGS[@]}"} \
+      "${NPM_CACHE_DOCKER_ARGS[@]}" \
       -e OPENCLAW_INSTALL_PACKAGE="$PACKAGE_NAME" \
       -e OPENCLAW_INSTALL_SMOKE_MODE=npm-global \
       -e OPENCLAW_INSTALL_UPDATE_BASELINE="$UPDATE_BASELINE_VERSION" \
@@ -389,6 +413,7 @@ LATEST_VERSION="${LATEST_VERSION:-}"
 if [[ "$SKIP_NONROOT" == "1" ]]; then
   echo "==> Skip non-root installer smoke (OPENCLAW_INSTALL_SMOKE_SKIP_NONROOT=1)"
 else
+  prepare_npm_cache
   if [[ "$SKIP_NONROOT_IMAGE_BUILD" == "1" ]]; then
     echo "==> Reuse prebuilt non-root image: $NONROOT_IMAGE"
   else
@@ -403,6 +428,7 @@ else
   echo "==> Run installer non-root test: $INSTALL_URL"
   docker run --rm -t \
     --platform "$NONROOT_PLATFORM" \
+    "${NPM_CACHE_DOCKER_ARGS[@]}" \
     -e OPENCLAW_INSTALL_URL="$INSTALL_URL" \
     -e OPENCLAW_INSTALL_PACKAGE="$PACKAGE_NAME" \
     -e OPENCLAW_INSTALL_METHOD=npm \
@@ -427,6 +453,7 @@ echo "==> Run CLI installer non-root test (same image)"
 docker run --rm -t \
   --platform "$NONROOT_PLATFORM" \
   --entrypoint /bin/bash \
+  "${NPM_CACHE_DOCKER_ARGS[@]}" \
   -e OPENCLAW_INSTALL_URL="$INSTALL_URL" \
   -e OPENCLAW_INSTALL_CLI_URL="$CLI_INSTALL_URL" \
   -e OPENCLAW_NO_ONBOARD=1 \
diff --git a/test/scripts/test-install-sh-docker.test.ts b/test/scripts/test-install-sh-docker.test.ts
index 6c8cd64e3e6..f602d10dca4 100644
--- a/test/scripts/test-install-sh-docker.test.ts
+++ b/test/scripts/test-install-sh-docker.test.ts
@@ -90,6 +90,9 @@ describe("install-sh smoke runner", () => {
     const runner = readFileSync(SMOKE_RUNNER_PATH, "utf8");
 
     expect(script).toContain('SKIP_NPM_GLOBAL="${OPENCLAW_INSTALL_SMOKE_SKIP_NPM_GLOBAL:-0}"');
+    expect(script).toContain('NPM_CACHE_DIR="${OPENCLAW_INSTALL_SMOKE_NPM_CACHE_DIR:-}"');
+    expect(script).toContain("-e npm_config_cache=/npm-cache");
+    expect(script).toContain('"${NPM_CACHE_DOCKER_ARGS[@]}"');
     expect(script).toContain("==> Run direct npm global smoke");
     expect(script).toContain("OPENCLAW_INSTALL_SMOKE_MODE=npm-global");
     expect(runner).toContain("run_npm_global_smoke");