diff --git a/app/git.js b/app/git.js
index fe11ac5..5006d88 100644
--- a/app/git.js
+++ b/app/git.js
@@ -14,6 +14,34 @@ function makeRunner(spawn) {
   };
 }
 
+/**
+ * Clone PR head branch to workspace/repo (idempotent)
+ */
+export function cloneRepo(workspace, _spawnSync = spawnSync) {
+  const run = makeRunner(_spawnSync);
+  const baseUrl = GITEA_SERVER_URL.replace(/\/$/, '');
+  const remoteUrl = `${baseUrl}/${GITEA_REPOSITORY}.git`;
+  const repoDir = path.join(workspace, 'repo');
+
+  const askpassScript = path.join(workspace, '.git-askpass.sh');
+  fs.writeFileSync(askpassScript, '#!/bin/sh\necho "$GIT_TOKEN"\n', { mode: 0o700 });
+  const credEnv = { ...process.env, GIT_ASKPASS: askpassScript, GIT_USERNAME: 'x-token', GIT_TOKEN: GITEA_TOKEN };
+
+  try {
+    if (!fs.existsSync(repoDir)) {
+      run(['clone', '--depth=1', '--branch', PR_HEAD_BRANCH, remoteUrl, repoDir], workspace, credEnv);
+      console.log(`  ✅ repo cloned to ${repoDir}`);
+    } else {
+      run(['fetch', 'origin', PR_HEAD_BRANCH], repoDir, credEnv);
+      run(['checkout', PR_HEAD_BRANCH], repoDir);
+      console.log(`  ✅ repo already exists, fetched latest`);
+    }
+  } finally {
+    try { fs.unlinkSync(askpassScript); } catch {}
+  }
+  return repoDir;
+}
+
 export async function commitAndPush(workspace, _spawnSync = spawnSync) {
   const run = makeRunner(_spawnSync);
 
diff --git a/app/main.js b/app/main.js
index ef0b173..b3bd670 100644
--- a/app/main.js
+++ b/app/main.js
@@ -3,7 +3,7 @@ import { loadRoles, getRoleIntro } from './roles.js';
 import { getPRDiff, postComment } from './gitea.js';
 import { analyzeWithRole, loadOldFindings, mergeFindings, sortByLevel, deduplicateWithAI, loadExclusions, applyExclusions } from './findings.js';
 import { saveFindings, postOldFindingsComment, postNewNonCriticalComment, postNewCriticalComments } from './comments.js';
-import { commitAndPush } from './git.js';
+import { cloneRepo, commitAndPush } from './git.js';
 
 const WORKSPACE = process.env.GITHUB_WORKSPACE || '/workspace';
 
@@ -65,7 +65,14 @@ async function main() {
 
   // Step3: 讀取舊 findings，合併去重（含 AI 語意去重）
   console.log('\n🔀 Step3: Findings 合併');
-  const oldFindings = loadOldFindings(WORKSPACE);
+  // Clone repo 以讀取舊 findings 與排除清單
+  let repoDir;
+  try {
+    repoDir = cloneRepo(WORKSPACE);
+  } catch (e) {
+    console.log(`  ⚠️  clone repo 失敗（繼續執行）: ${e.message}`);
+  }
+  const oldFindings = loadOldFindings(repoDir || WORKSPACE);
   const mergedFindings = mergeFindings(oldFindings, newFindings);
   console.log(`  Step3 merged findings total=${mergedFindings.length}`);
 
@@ -76,7 +83,7 @@ async function main() {
 
   // Step4: 讀取排除問題檔案，過濾 PR 問題表格
   console.log('\n🚫 Step4: 排除問題過濾');
-  const exclusions = loadExclusions(WORKSPACE);
+  const exclusions = loadExclusions(repoDir || WORKSPACE);
   const filtered = applyExclusions(sorted, exclusions);
   console.log(`  Step4 完成: findings total=${filtered.length}`);