diff --git a/web-to-ppt/background.js b/web-to-ppt/background.js
index d5f36db..afc96d3 100644
--- a/web-to-ppt/background.js
+++ b/web-to-ppt/background.js
@@ -146,6 +146,17 @@ chrome.runtime.onMessage.addListener((message, sender, sendResponse) => {
       assertCaptureableTab(tab);
       const data = await captureCurrentTab(tab, settings);
       lastCaptureData = data;
+      // 保存 JSON 供调试
+      try {
+        const json = JSON.stringify(data, null, 2);
+        const encoded = btoa(unescape(encodeURIComponent(json)));
+        const title = data.source?.title || 'debug';
+        const safe = title.replace(/[\\/:*?"<>|]+/g, '-').slice(0, 32);
+        chrome.downloads.download({
+          url: 'data:application/json;base64,' + encoded,
+          filename: 'web-to-ppt/' + safe + '-' + Date.now() + '.json'
+        });
+      } catch(e) {}
       return { ok: true, actualViewportWidth: data.source?.actualViewportWidth };
     })()
       .then(sendResponse)