diff --git a/src/main/java/org/shop/crop/CropController.java b/src/main/java/org/shop/crop/CropController.java
index 730a24e..1eb9039 100644
--- a/src/main/java/org/shop/crop/CropController.java
+++ b/src/main/java/org/shop/crop/CropController.java
@@ -56,7 +56,7 @@ public class CropController {
 
 
     @GetMapping("/crop/chatData")
-    public List<CropMessage> chatData(Long startSeq,String corpId) throws IOException {
+    public List<CropMessage> chatData(Long startSeq, String corpId) throws IOException {
         long limit = 1000;
         long slice = Finance.NewSlice();
         Long sdk = sdkManager.initSdk(corpId, "mEizahrSF6axdfWtSK_f73a3j6-sV02hhyGG7ogmTpM");
@@ -69,7 +69,7 @@ public class CropController {
         }
         String contentResult = Finance.GetContentFromSlice(slice);
         log.info("内容字符串" + contentResult);
-        return decodeChatData(contentResult,startSeq,sdk,corpId);
+        return decodeChatData(contentResult, startSeq, sdk, corpId);
     }
 
     /**
@@ -77,7 +77,7 @@ public class CropController {
      *
      * @param contentResult 拉取到的JSON原文
      */
-    public List<CropMessage> decodeChatData(String contentResult,Long startSeq,Long sdk,String corpId) throws IOException {
+    public List<CropMessage> decodeChatData(String contentResult, Long startSeq, Long sdk, String corpId) throws IOException {
         // 1.基础信息解析
         List<CropMessage> messageList = new ArrayList<>();
         MessagePullResponse messagePullResponse = JSON.parseObject(contentResult, MessagePullResponse.class);
@@ -92,7 +92,7 @@ public class CropController {
         }
         String privateKey = StreamUtils.copyToString(resource.getInputStream(), StandardCharsets.UTF_8);
         // 3. 提取所有 seq
-        log.info("chatdataList={} 加密数据",chatdataList);
+        log.info("chatdataList={} 加密数据", chatdataList);
         // 4. 查询数据库中已存在的 seq
         // 直接在业务代码中（或封装到 service）
         List<Long> existingSeqs = cropMessageService.lambdaQuery()
@@ -103,9 +103,9 @@ public class CropController {
                 .map(CropMessage::getSeq)
                 .collect(Collectors.toList());
         Set<Long> existingSeqSet = new HashSet<>(existingSeqs);
-        log.info("existingSeqSet={} 加密数据",existingSeqSet);
+        log.info("existingSeqSet={} 加密数据", existingSeqSet);
 
-        CropConfig config=cropConfigMapper.selectById(1);
+        CropConfig config = cropConfigMapper.selectById(1);
         Long maxSeq = config.getLastSeq();
         // 改为：
         List<CropFile> mediaFileInfos = new ArrayList<>();
@@ -117,7 +117,7 @@ public class CropController {
             }
             try {
                 // 解密ChatData数据
-                String plainTextJson = decrypt(chatData, privateKey,sdk);
+                String plainTextJson = decrypt(chatData, privateKey, sdk);
                 BaseMessageDto messageDto = JSON.parseObject(plainTextJson, BaseMessageDto.class);
                 // 转换dto数据到entity
                 CropMessage message = messageDto.convertToMessage();
@@ -140,8 +140,9 @@ public class CropController {
         }
 
 
-        return saveData(messageList,maxSeq,config,mediaFileInfos,sdk,corpId);
+        return saveData(messageList, maxSeq, config, mediaFileInfos, sdk, corpId);
     }
+
     /**
      * 异步下载待处理的媒体文件
      *
@@ -149,7 +150,7 @@ public class CropController {
      */
     @Transactional
     public List<CropMessage> saveData(List<CropMessage> messageList, Long maxSeq, CropConfig config
-            , List<CropFile>mediaFileInfos,Long sdk,String corpId) {
+            , List<CropFile> mediaFileInfos, Long sdk, String corpId) {
 
         // 4.保存消息和失败任务
         cropMessageService.saveBatch(messageList);
@@ -164,6 +165,7 @@ public class CropController {
                 mf.setSeq(info.getSeq());
                 mf.setCropId(corpId);
                 mf.setStatus(0);
+                mf.setExt(info.getExt());
                 return mf;
             }).collect(Collectors.toList());
 
@@ -172,18 +174,20 @@ public class CropController {
 
             // ✅ 异步触发下载任务（可以轮询数据库）
             CompletableFuture.runAsync(() -> {
-                downloadPendingFiles(mediaFiles,sdk); // 也可以不传参，改为查数据库
+                downloadPendingFiles(mediaFiles, sdk); // 也可以不传参，改为查数据库
             });
         }
         return messageList;
     }
+
     /**
      * 异步下载待处理的媒体文件
      */
-    private void downloadPendingFiles(List<CropFile> mediaFiles,Long sdk) {
+    private void downloadPendingFiles(List<CropFile> mediaFiles, Long sdk) {
         for (CropFile mf : mediaFiles) {
             try {
-                String url = downFile(mf.getSdkFileId(), mf.getMsgType(),sdk);
+                String msgType = getSuffixByMsgType(mf);
+                String url = downFile(mf.getSdkFileId(), msgType, sdk);
                 if (url != null && !url.isEmpty()) {
                     mf.setUrl(url);
                     mf.setStatus(1);
@@ -201,6 +205,7 @@ public class CropController {
             }
         }
     }
+
     /**
      * 提取所有需要下载的媒体文件信息
      */
@@ -230,10 +235,17 @@ public class CropController {
                     if (msg.containsKey(msgType)) {
                         String sdkFileId = msg.getJSONObject(msgType).getString("sdkfileid");
                         if (sdkFileId != null && !sdkFileId.trim().isEmpty()) {
-                            CropFile cropFile = new CropFile(); // 注意：你写成了 CropConfig，应为 CropFile
+                            CropFile cropFile = new CropFile();
                             cropFile.setMsgType(msgType);
                             cropFile.setSeq(seq);
                             cropFile.setSdkFileId(sdkFileId);
+                            cropFile.setSeq(seq);
+                            cropFile.setExt(msgType);
+                            if (msgType.equals("file")) {
+                                String fileext = msg.getJSONObject(msgType).getString("fileext");
+                                cropFile.setExt(fileext);
+                            }
+
                             result.add(cropFile);
                         }
                     }
@@ -246,9 +258,11 @@ public class CropController {
     }
 
     @GetMapping("/crop/downFile")
-    public String downFile(String sdkField,String msgType,Long sdk) throws IOException {
-        File tempFile = File.createTempFile(GlobalConstants.DOWNLOAD_TEMP_FILE_NAME_PREFIX ,
-                getSuffixByMsgType(msgType), mediaContext.getTempMergeFileDir());
+    public String downFile(String sdkField, String msgType, Long sdk) throws IOException {
+        File tempFile = File.createTempFile(GlobalConstants.DOWNLOAD_TEMP_FILE_NAME_PREFIX,
+                msgType, mediaContext.getTempMergeFileDir());
+        sdk = sdkManager.initSdk("ww64f47cd0afc456a5", "mEizahrSF6axdfWtSK_f73a3j6-sV02hhyGG7ogmTpM");
+
         String indexbuf = null; // 初始化 indexbuf
         try (FileOutputStream fileOutputStream = new FileOutputStream(tempFile)) {
             while (true) {
@@ -273,8 +287,8 @@ public class CropController {
         return "";
     }
 
-    public String getSuffixByMsgType(String msgType) {
-        switch (msgType) {
+    public String getSuffixByMsgType(CropFile cropFile) {
+        switch (cropFile.getMsgType()) {
             case "image":
                 return ".jpg";
             case "voice":
@@ -282,7 +296,7 @@ public class CropController {
             case "video":
                 return ".mp4";
             case "file":
-                return ".bin";
+                return "." + cropFile.getExt(); // 取真实后缀
             default:
                 return ".bin";
         }
@@ -296,7 +310,7 @@ public class CropController {
      * @param privateKeyStr 私钥字符串
      * @return 解密后的原文
      */
-    private String decrypt(ChatData chatData, String privateKeyStr,Long sdk) throws Exception {
+    private String decrypt(ChatData chatData, String privateKeyStr, Long sdk) throws Exception {
         // 1.解密EncryptRandomKey
         String randomKey = EncodeUtils.decryptRandomKey(chatData.getEncryptRandomKey(), privateKeyStr);
         // 2.调用SDK方法解密密文数据
diff --git a/src/main/java/org/shop/crop/dao/CropFile.java b/src/main/java/org/shop/crop/dao/CropFile.java
index 0601b14..fe90cee 100644
--- a/src/main/java/org/shop/crop/dao/CropFile.java
+++ b/src/main/java/org/shop/crop/dao/CropFile.java
@@ -23,7 +23,7 @@ public class CropFile {
 
     private String url;               // 下载后上传 OSS 的地址
 
-    private String fileName;          // 可选：原始文件名（后续可补充）
+    private String ext;          // 可选：原始文件名（后续可补充）
 
     private Integer status = 0; // 0 pending, 1 success, 2 failed