diff --git a/src/main/java/com/threecloud/dataserviceyy/service/VaaSyncService.java b/src/main/java/com/threecloud/dataserviceyy/service/VaaSyncService.java
index ffc7fc9..6d012da 100644
--- a/src/main/java/com/threecloud/dataserviceyy/service/VaaSyncService.java
+++ b/src/main/java/com/threecloud/dataserviceyy/service/VaaSyncService.java
@@ -214,9 +214,12 @@ public class VaaSyncService {
             }
         }
 
-        // 步骤6：保存同步时间（用API返回的最大时间，而非仅新处理的时间）
-        if (latestCallTime != null) {
+        // 只有本轮全部处理成功才推进游标，避免失败录音被同步时间跨过去而永久漏拉。
+        // 下轮重复查询到的成功记录会通过 callRecordId 防重跳过。
+        if (latestCallTime != null && failCount == 0) {
             SyncTimeUtil.writeLastSyncTime(downloadPath, deviceId, latestCallTime);
+        } else if (failCount > 0) {
+            logger.warn("【设备】本轮有{}条录音失败，不推进同步时间，下轮将重新查询", failCount);
         }
 
         logger.info("【设备】同步完成: ID={}, 成功{}条, 失败{}条", deviceId, successCount, failCount);
@@ -226,7 +229,7 @@ public class VaaSyncService {
      * 处理单条录音记录
      *
      * OSS存储路径: voice/{cityCode}/{yyyy-MM-dd}/{fileName}
-     * 上传失败不阻塞：记录仍保存到数据库，文件路径留空
+     * 下载、校验、OSS上传全部成功后才保存数据库记录。
      *
      * @return 通话开始时间（成功时），null表示跳过
      */
@@ -277,24 +280,15 @@ public class VaaSyncService {
                 (int) (endTime - begTime), channelPhone, phone, isOutgoing, isAnswered);
 
         // 下载录音文件（无重试）
-        // 文件不存在、大小为0、或小于1KB（可能损坏）时重新下载
-        boolean needDownload = !Files.exists(localFile) || Files.size(localFile) < 1024;
-        // 额外校验：已存在文件也可能是HTML错误页面，检查文件头
+        // 文件不存在或完整性校验失败时重新下载。
+        boolean needDownload = !Files.exists(localFile);
         if (!needDownload) {
             try {
-                byte[] header = new byte[16];
-                try (java.io.RandomAccessFile raf = new java.io.RandomAccessFile(localFile.toFile(), "r")) {
-                    raf.readFully(header);
-                }
-                String headerStr = new String(header, "ASCII").trim().toLowerCase();
-                if (headerStr.startsWith("<!doctype") || headerStr.startsWith("<html")) {
-                    logger.warn("【录音】本地文件为HTML页面，重新下载: {}", fileName);
-                    needDownload = true;
-                    Files.delete(localFile);
-                }
+                vaaHttpUtil.validateAudioFile(localFile.toFile());
             } catch (Exception e) {
-                logger.warn("【录音】校验本地文件失败，重新下载: {}", fileName);
+                logger.warn("【录音】本地文件校验失败，重新下载: {}, 原因={}", fileName, e.getMessage());
                 needDownload = true;
+                Files.deleteIfExists(localFile);
             }
         }
         if (needDownload) {
@@ -306,17 +300,15 @@ public class VaaSyncService {
         }
         callRecord.setRecordingFileSize((int) Files.size(localFile));
 
-        // 上传到OSS（地市+日期目录），上传失败不阻塞，仍保存通话记录
+        // 上传到OSS（地市+日期目录）；上传失败时整条处理失败，下轮重新拉取。
         String ossPath = "voice/" + cityCode + "/" + new SimpleDateFormat("yyyy-MM-dd").format(callStartTime) + "/";
-        try {
-            OssFileResponse ossResponse = ossFileService.uploadFile(localFile.toFile(), fileName, ossPath);
-            String previewUrl = ossResponse.getFileUrl();
-            callRecord.setRecordingFilePath(previewUrl);
-            logger.info("【录音】OSS上传成功: {}", previewUrl);
-        } catch (Exception e) {
-            logger.error("【录音】OSS上传失败，通话记录仍将保存: fileName={}, 原因={}", fileName, e.getMessage());
-            callRecord.setRecordingFilePath(null);
+        OssFileResponse ossResponse = ossFileService.uploadFile(localFile.toFile(), fileName, ossPath);
+        String previewUrl = ossResponse.getFileUrl();
+        if (previewUrl == null || previewUrl.trim().isEmpty()) {
+            throw new IllegalStateException("OSS上传成功但未返回文件地址: " + fileName);
         }
+        callRecord.setRecordingFilePath(previewUrl);
+        logger.info("【录音】OSS上传成功: {}", previewUrl);
 
         // 保存到数据库
         callRecordMapper.insert(callRecord);
@@ -444,4 +436,4 @@ public class VaaSyncService {
         try { return Integer.parseInt(v.toString()); }
         catch (NumberFormatException e) { return defaultVal; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/threecloud/dataserviceyy/util/VaaHttpUtil.java b/src/main/java/com/threecloud/dataserviceyy/util/VaaHttpUtil.java
index 501b6d6..76dfc65 100644
--- a/src/main/java/com/threecloud/dataserviceyy/util/VaaHttpUtil.java
+++ b/src/main/java/com/threecloud/dataserviceyy/util/VaaHttpUtil.java
@@ -9,6 +9,11 @@ import org.springframework.stereotype.Component;
 import java.io.*;
 import java.net.HttpURLConnection;
 import java.net.URL;
+import java.nio.file.AtomicMoveNotSupportedException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardCopyOption;
+import java.util.Locale;
 import java.util.List;
 import java.util.Map;
 
@@ -124,16 +129,15 @@ public class VaaHttpUtil {
     public void httpDown(String fileUrl, String savePath, String authorization) throws Exception {
         logger.info("开始下载录音文件: {} -> {}", fileUrl, savePath);
 
-        // 确保目录存在
         File saveFile = new File(savePath);
-        if (!saveFile.getParentFile().exists()) {
-            saveFile.getParentFile().mkdirs();
+        File parentDir = saveFile.getParentFile();
+        if (!parentDir.exists() && !parentDir.mkdirs() && !parentDir.exists()) {
+            throw new IOException("创建录音目录失败: " + parentDir.getAbsolutePath());
         }
+        File partFile = new File(savePath + ".part");
+        Files.deleteIfExists(partFile.toPath());
 
         HttpURLConnection conn = null;
-        InputStream inputStream = null;
-        FileOutputStream outputStream = null;
-
         try {
             URL url = new URL(fileUrl);
             conn = (HttpURLConnection) url.openConnection();
@@ -147,59 +151,91 @@ public class VaaHttpUtil {
                 // 获取服务器声明的文件大小，用于完整性校验
                 long expectedSize = conn.getContentLengthLong();
 
-                inputStream = conn.getInputStream();
-                outputStream = new FileOutputStream(savePath);
-
                 byte[] buffer = new byte[8192];
-                int bytesRead;
                 long totalBytes = 0;
-
-                while ((bytesRead = inputStream.read(buffer)) != -1) {
-                    outputStream.write(buffer, 0, bytesRead);
-                    totalBytes += bytesRead;
+                try (InputStream inputStream = conn.getInputStream();
+                     FileOutputStream outputStream = new FileOutputStream(partFile)) {
+                    int bytesRead;
+                    while ((bytesRead = inputStream.read(buffer)) != -1) {
+                        outputStream.write(buffer, 0, bytesRead);
+                        totalBytes += bytesRead;
+                    }
+                    outputStream.getFD().sync();
                 }
-
-                outputStream.flush();
                 logger.info("录音文件下载完成: {}, 大小: {} bytes ({} MB)",
-                        savePath, totalBytes, totalBytes / 1024 / 1024);
+                        partFile.getAbsolutePath(), totalBytes, totalBytes / 1024 / 1024);
 
                 // 完整性校验
                 if (expectedSize > 0 && totalBytes != expectedSize) {
-                    saveFile.delete();
                     throw new RuntimeException(String.format(
                             "文件下载不完整: 期望 %d bytes, 实际 %d bytes", expectedSize, totalBytes));
                 }
-                // 录音文件至少应有1KB，过小说明下载异常
-                if (totalBytes < 1024) {
-                    saveFile.delete();
-                    throw new RuntimeException(String.format(
-                            "文件过小，可能下载异常: 仅 %d bytes", totalBytes));
-                }
-                // 校验文件头，确保不是HTML错误页面
-                byte[] header = new byte[(int) Math.min(totalBytes, 16)];
-                try (java.io.RandomAccessFile raf = new java.io.RandomAccessFile(saveFile, "r")) {
-                    raf.readFully(header);
-                }
-                String headerStr = new String(header, "ASCII").trim().toLowerCase();
-                if (headerStr.startsWith("<!doctype") || headerStr.startsWith("<html")) {
-                    saveFile.delete();
-                    throw new RuntimeException("下载内容为HTML页面，非音频文件");
-                }
+                validateAudioFile(partFile);
+                moveAtomically(partFile.toPath(), saveFile.toPath());
             } else {
                 throw new RuntimeException("文件下载失败，HTTP状态码: " + responseCode);
             }
+        } catch (Exception e) {
+            try {
+                Files.deleteIfExists(partFile.toPath());
+            } catch (IOException cleanupError) {
+                e.addSuppressed(cleanupError);
+            }
+            throw e;
         } finally {
-            closeQuietly(inputStream);
-            closeQuietly(outputStream);
             if (conn != null) {
                 conn.disconnect();
             }
         }
     }
 
-    private void closeQuietly(Closeable c) {
-        if (c != null) {
-            try { c.close(); } catch (IOException ignored) {}
+    /** 校验本地文件至少完整到可识别为对应音频格式。 */
+    public void validateAudioFile(File file) throws IOException {
+        if (file == null || !file.isFile() || file.length() < 1024) {
+            throw new IOException("录音文件不存在或小于1KB: " + (file == null ? "null" : file.getPath()));
+        }
+        byte[] header = new byte[12];
+        try (RandomAccessFile raf = new RandomAccessFile(file, "r")) {
+            raf.readFully(header);
+        }
+        String text = new String(header, "ISO-8859-1").trim().toLowerCase(Locale.ROOT);
+        if (text.startsWith("<!doctype") || text.startsWith("<html")) {
+            throw new IOException("下载内容为HTML页面，非音频文件");
+        }
+
+        String name = file.getName().toLowerCase(Locale.ROOT);
+        if (name.endsWith(".part")) {
+            name = name.substring(0, name.length() - ".part".length());
+        }
+        if (name.endsWith(".wav")) {
+            boolean riffWave = header[0] == 'R' && header[1] == 'I' && header[2] == 'F' && header[3] == 'F'
+                    && header[8] == 'W' && header[9] == 'A' && header[10] == 'V' && header[11] == 'E';
+            if (!riffWave) {
+                throw new IOException("WAV文件头无效: " + file.getPath());
+            }
+            long riffDataSize = ((long) header[4] & 0xFF)
+                    | (((long) header[5] & 0xFF) << 8)
+                    | (((long) header[6] & 0xFF) << 16)
+                    | (((long) header[7] & 0xFF) << 24);
+            long declaredFileSize = riffDataSize + 8;
+            if (declaredFileSize > file.length()) {
+                throw new IOException(String.format(
+                        "WAV文件被截断: 声明 %d bytes, 实际 %d bytes", declaredFileSize, file.length()));
+            }
+        } else if (name.endsWith(".mp3")) {
+            boolean id3 = header[0] == 'I' && header[1] == 'D' && header[2] == '3';
+            boolean frameSync = (header[0] & 0xFF) == 0xFF && (header[1] & 0xE0) == 0xE0;
+            if (!id3 && !frameSync) {
+                throw new IOException("MP3文件头无效: " + file.getPath());
+            }
+        }
+    }
+
+    private void moveAtomically(Path source, Path target) throws IOException {
+        try {
+            Files.move(source, target, StandardCopyOption.ATOMIC_MOVE, StandardCopyOption.REPLACE_EXISTING);
+        } catch (AtomicMoveNotSupportedException e) {
+            Files.move(source, target, StandardCopyOption.REPLACE_EXISTING);
         }
     }