diff --git a/action.yml b/action.yml
index 4f8ff679..4708531a 100644
--- a/action.yml
+++ b/action.yml
@@ -24,12 +24,19 @@ branding:
 runs:
   using: composite
   steps:
-    # Set up the version of Python that supports pyodide
-    - uses: actions/setup-python@v5
-      id: python
-      with:
-        python-version: "3.12"
-        update-environment: false
+    # PATCHED for self-hosted runner (offline): 原 actions/setup-python@v5 需联网校验
+    # versions manifest，内网不可达；直接使用 toolcache 预置的 Python 3.12
+    - id: python
+      run: |
+        for p in /opt/hostedtoolcache/Python/3.12*/x64/bin/python3.12 /usr/bin/python3.12 /usr/bin/python3; do
+          if [ -x "$p" ]; then
+            echo "python-path=$p" >> "$GITHUB_OUTPUT"
+            exit 0
+          fi
+        done
+        echo "no usable python found" >&2
+        exit 1
+      shell: bash
 
     - id: cibw
       run: |