diff --git a/.github/workflows/close-issue-on-pr-merge.yml b/.github/workflows/close-issue-on-pr-merge.yml
new file mode 100644
index 0000000..b7e4894
--- /dev/null
+++ b/.github/workflows/close-issue-on-pr-merge.yml
@@ -0,0 +1,70 @@
+# PR 合并后自动关闭关联的 Issue
+# 当 PR 从 ai_fix/N_xxx 分支合并到 main 时，关闭 #N 对应的 Issue（若 PR 描述中未含 Closes #N 则通过分支名解析）
+
+name: Close issue on PR merge
+
+on:
+  pull_request:
+    types: [closed]
+    branches: [main]
+
+jobs:
+  close-issue:
+    if: github.event.pull_request.merged == true
+    runs-on: ubuntu-latest
+    permissions:
+      issues: write
+      pull-requests: read
+
+    steps:
+      - name: Get PR info
+        id: pr
+        run: |
+          # 从 PR body 查找 Closes #N / Fixes #N（若已有则 GitHub 已自动关 issue，本 step 仅做解析）
+          BODY="${{ github.event.pull_request.body }}"
+          HEAD_REF="${{ github.event.pull_request.head.ref }}"
+
+          # 优先从 PR 描述解析
+          ISSUE_NUM=$(echo "$BODY" | grep -oE '(Closes|Fixes|Resolves) #([0-9]+)' | head -1 | grep -oE '[0-9]+')
+          if [ -z "$ISSUE_NUM" ]; then
+            # 从分支名解析 ai_fix/N_xxx
+            ISSUE_NUM=$(echo "$HEAD_REF" | sed -n 's|^ai_fix/\([0-9]*\)_.*|\1|p')
+          fi
+
+          if [ -z "$ISSUE_NUM" ]; then
+            echo "ISSUE_NUMBER=" >> $GITHUB_OUTPUT
+            echo "skip=true" >> $GITHUB_OUTPUT
+            echo "未从 PR 描述或分支名解析到 Issue 编号，跳过关闭"
+            exit 0
+          fi
+
+          echo "ISSUE_NUMBER=$ISSUE_NUM" >> $GITHUB_OUTPUT
+          echo "skip=false" >> $GITHUB_OUTPUT
+          echo "解析到 Issue #$ISSUE_NUM"
+
+      - name: Close issue
+        if: steps.pr.outputs.skip != 'true'
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const issueNumber = parseInt('${{ steps.pr.outputs.ISSUE_NUMBER }}', 10);
+            if (!issueNumber || isNaN(issueNumber)) {
+              console.log('No valid issue number, skip');
+              return;
+            }
+            const { data: issue } = await github.rest.issues.get({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: issueNumber
+            });
+            if (issue.state === 'open') {
+              await github.rest.issues.update({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: issueNumber,
+                state: 'closed'
+              });
+              console.log(`Issue #${issueNumber} closed.`);
+            } else {
+              console.log(`Issue #${issueNumber} already closed.`);
+            }