diff --git a/README.md b/README.md
index 0d9d407..e9fc25b 100644
--- a/README.md
+++ b/README.md
@@ -28,9 +28,12 @@ evanEnv.enableAutoDownload = true
 
 ## FFmpeg合并示例
 ```shell
-ffmpeg -i mediasource_0_0.mp4 -i mediasource_0_1.mp4 -c copy -bsf:a aac_adtstoasc out.mp4
+ffmpeg -i mediasource_0_0_0.mp4 -i mediasource_0_1_0.mp4 -c copy -bsf:a aac_adtstoasc out.mp4
 ```
 
+## 大文件分段需要先文件合并
+copy /b mediasource_0_0_*.mp4 out.mp4
+
 ## 常见问题
 - 合并后声音播放不正常:由于部分网站使用了HE-AAC v2(AAC+SBR+PS)作为音频编码,大部分播放器还不支持此音频流格式,故声音不正常,使用Windows自带的视频播放器播放正常
 
diff --git a/downloadMedia.js b/downloadMedia.js
index 11b80c6..d907510 100644
--- a/downloadMedia.js
+++ b/downloadMedia.js
@@ -19,29 +19,44 @@ evanEnv.enableAutoDownload = true;
 
 (function () {
     evanEnv.videos = document.getElementsByTagName('video');
-    evanEnv.buildArrayBuffer = function (bufferList) {
+    evanEnv.downloadRawData = function (bufferList, fileName = 'out', ext = '.mp4') {
+        var buffList = new Array();
         var totalLength = 0;
+
         for (var i = 0; i < bufferList.length; i++) {
             totalLength += bufferList[i].byteLength;
+            if (totalLength > 1073741824 || i == bufferList.length - 1) {
+                buffList.push(new Uint8Array(totalLength));
+                totalLength = 0;
+            }
         }
-        var tmp = new Uint8Array(totalLength);
+
         var lastLength = 0;
+        var part = 0;
         for (var ix = 0; ix < bufferList.length; ix++) {
-            tmp.set(new Uint8Array(bufferList[ix]), lastLength);
+            //10485760
+            //1073741824
+
+            buffList[part].set(new Uint8Array(bufferList[ix]), lastLength);
             lastLength += bufferList[ix].byteLength;
+            if (lastLength > 1073741824) {
+                part++;
+                lastLength = 0
+            }
         }
-        return tmp.buffer;
-    };
-    evanEnv.downloadRawData = function (bufferList, fileName = 'out.mp4') {
-        var buff = evanEnv.buildArrayBuffer(bufferList);
-        let url = window.URL.createObjectURL(new Blob([buff], {type: "arraybuffer"}))
-        const link = document.createElement('a');
-        link.style.display = 'none';
-        link.href = url;
-        link.setAttribute('download', fileName);
-        document.body.appendChild(link);
-        link.click();
-        document.body.removeChild(link);
+
+        for (var iz = 0; iz < buffList.length; iz++) {
+            var buff = buffList[iz];
+            let url = window.URL.createObjectURL(new Blob([buff], { type: "arraybuffer" }))
+            const link = document.createElement('a');
+            link.style.display = 'none';
+            link.href = url;
+            link.setAttribute('download', fileName + "_" + iz + ext);
+            document.body.appendChild(link);
+            link.click();
+            document.body.removeChild(link);
+        }
+
     };
 
     evanEnv.download = function () {
@@ -49,7 +64,7 @@ evanEnv.enableAutoDownload = true;
             var currentItem = evanEnv.mediaSources[i];
             if (currentItem.downloaded == undefined || currentItem.downloaded == false) {
                 for (var x = 0; x < currentItem.rawSources.length; x++) {
-                    evanEnv.downloadRawData(currentItem.rawSources[x], 'mediasource_' + i + '_' + x + '.mp4');
+                    evanEnv.downloadRawData(currentItem.rawSources[x], 'mediasource_' + i + '_' + x);
                 }
             }
             currentItem.downloaded = true;
@@ -57,7 +72,7 @@ evanEnv.enableAutoDownload = true;
     };
     evanEnv.downloadMediaSource = function (mediaSource) {
         for (var x = 0; x < mediaSource.rawSources.length; x++) {
-            evanEnv.downloadRawData(mediaSource.rawSources[x], 'mediasource_' + x + '.mp4');
+            evanEnv.downloadRawData(mediaSource.rawSources[x], 'mediasource_' + x);
             mediaSource.downloaded = true;
         }
     };