diff --git a/action.yml b/action.yml
index 0cdf862..d5d8c04 100644
--- a/action.yml
+++ b/action.yml
@@ -2,39 +2,25 @@
 name: "build docker image and push to code"
 description: "build docker image and push to simcu code"
 inputs:
-  dockerfile:
-    description: "if set, will use this to build"
+  context:
+    description: "构建目录（相对仓库根目录，默认 .）。例如后端在 dotnet 目录下时填 dotnet"
     required: false
-    default: ""
+    default: "."
 runs:
   using: "composite"
   steps:
     - name: build .net app
       uses: docker://mcr.microsoft.com/dotnet/sdk:10.0
-      with:
-        args: dotnet publish -r linux-x64 -c Release --self-contained -o dist -p:AssemblyName=App -p:Version=${{ github.ref_name }}
-
-    - name: create dockerfile
-      if: ${{ inputs.dockerfile == '' }}
-      uses: docker://ubuntu:latest
       with:
         entrypoint: "/bin/bash"
         args: |
-          -c 'echo "FROM mcr.microsoft.com/dotnet/runtime:10.0" > Dockerfile && \
-           echo "ENV TZ Asia/Shanghai" >> Dockerfile && \
-           echo "COPY dist /home" >> Dockerfile && \
-           echo "WORKDIR /home" >> Dockerfile && \
-           echo "ENTRYPOINT [\"./App\"]" >> Dockerfile && \
-           echo "已经构建完DOCKERFILE了" && \
-           cat Dockerfile'
+          -c 'cd "${{ inputs.context }}" && \
+          dotnet publish -r linux-x64 -c Release --self-contained -o dist -p:AssemblyName=App -p:Version=${{ github.ref_name }}'
 
-    - name: build docker image use custom dockerfile
-      uses: docker://docker:git
+    # -f 直接指向本 action 内置的 dotnet.Dockerfile，不用再准备/拷贝文件；
+    # 构建上下文仍是 context，所以 Dockerfile 里的 COPY dist 取的是构建目录下的发布产物
+    - name: build docker image and push
+      uses: actions/docker-build-push@main
       with:
-        entrypoint: "/bin/sh"
-        args: |
-          -c 'cat ${{ inputs.dockerfile || 'Dockerfile' }} && docker build -t ${{vars.DOCKER_REGISTRY}}/${{github.repository}}:${{ github.ref_name }} -f ${{ inputs.dockerfile || 'Dockerfile' }} . && \
-             echo ${{vars.DOCKER_REGISTRY}}/${{github.repository}}:${{ github.ref_name }}已经构建完了 && \
-             docker login ${{vars.DOCKER_REGISTRY}} -u ${{vars.DOCKER_USER}} -p ${{vars.DOCKER_PASS}} && \
-             docker push ${{vars.DOCKER_REGISTRY}}/${{github.repository}}:${{ github.ref_name }} && \
-             echo ${{vars.DOCKER_REGISTRY}}/${{github.repository}}:${{ github.ref_name }}推送成功'
+        context: ${{ inputs.context }}
+        dockerfile: ${{ github.action_path }}/dotnet.Dockerfile
diff --git a/dotnet.Dockerfile b/dotnet.Dockerfile
new file mode 100644
index 0000000..d275448
--- /dev/null
+++ b/dotnet.Dockerfile
@@ -0,0 +1,5 @@
+FROM mcr.microsoft.com/dotnet/runtime:10.0
+ENV TZ Asia/Shanghai
+COPY dist /home
+WORKDIR /home
+ENTRYPOINT ["./App"]