diff --git a/src/main/java/com/threecloud/dataserviceyy/mapper/MidVoiceCallRecordMapper.java b/src/main/java/com/threecloud/dataserviceyy/mapper/MidVoiceCallRecordMapper.java
index 9b29032..ac68277 100644
--- a/src/main/java/com/threecloud/dataserviceyy/mapper/MidVoiceCallRecordMapper.java
+++ b/src/main/java/com/threecloud/dataserviceyy/mapper/MidVoiceCallRecordMapper.java
@@ -26,6 +26,14 @@ public interface MidVoiceCallRecordMapper {
      * 根据通话记录ID查询（防止重复插入）
      */
     MidVoiceCallRecord selectByCallRecordId(@Param("callRecordId") String callRecordId);
+
+    /**
+     * 批量查询某设备在时间范围内的已存在call_record_id
+     * 用于防重复：一次查询代替N次单条查询
+     */
+    List<String> selectExistingCallRecordIds(@Param("deviceNo") String deviceNo,
+                                              @Param("startTime") String startTime,
+                                              @Param("endTime") String endTime);
     
     /**
      * 根据设备编码查询
diff --git a/src/main/java/com/threecloud/dataserviceyy/service/VaaSyncService.java b/src/main/java/com/threecloud/dataserviceyy/service/VaaSyncService.java
index 737e7f0..7559f9e 100644
--- a/src/main/java/com/threecloud/dataserviceyy/service/VaaSyncService.java
+++ b/src/main/java/com/threecloud/dataserviceyy/service/VaaSyncService.java
@@ -175,6 +175,13 @@ public class VaaSyncService {
         }
         logger.info("【设备】获取到 {} 条录音记录", records.size());
 
+        // 批量查询已存在的call_record_id（一次查询代替N次，防重复性能优化）
+        String startTimeStr = DateUtil.formatDate(lastSyncTime, "yyyy-MM-dd HH:mm:ss");
+        String endTimeStr = DateUtil.formatDate(now, "yyyy-MM-dd HH:mm:ss");
+        Set<String> existingIds = new HashSet<>(callRecordMapper.selectExistingCallRecordIds(
+                deviceNo, startTimeStr, endTimeStr));
+        logger.debug("【设备】已存在 {} 条通话记录，将跳过", existingIds.size());
+
         // 步骤5：逐条处理录音
         int successCount = 0;
         int failCount = 0;
@@ -184,7 +191,7 @@ public class VaaSyncService {
             JSONObject rec = records.getJSONObject(i);
             try {
                 Date callTime = processSingleRecord(rec, deviceNo, cityName, cityCode, orgCode,
-                        deviceHost, authToken, extNumbers);
+                        deviceHost, authToken, extNumbers, existingIds);
                 if (callTime != null) {
                     successCount++;
                     if (latestCallTime == null || callTime.after(latestCallTime)) {
@@ -212,7 +219,8 @@ public class VaaSyncService {
      */
     private Date processSingleRecord(JSONObject rec, String deviceNo, String cityName,
                                       String cityCode, String orgCode, String deviceHost,
-                                      String authToken, Map<String, String> extNumbers) throws Exception {
+                                      String authToken, Map<String, String> extNumbers,
+                                      Set<String> existingIds) throws Exception {
         // 解析录音信息
         String recordId = RecordParser.parseRecordId(rec);
         String filePath = RecordParser.parseFilePath(rec);
@@ -231,9 +239,9 @@ public class VaaSyncService {
             return null;
         }
 
-        // 防重复：根据 device_no + record_id 判断
+        // 防重复：内存中比对已存在的call_record_id（一次查询代替N次）
         String callRecordId = deviceNo + "_" + recordId;
-        if (callRecordMapper.selectByCallRecordId(callRecordId) != null) {
+        if (existingIds.contains(callRecordId)) {
             logger.debug("【录音】已存在，跳过: {}", callRecordId);
             return null;
         }
diff --git a/src/main/resources/mapper/MidVoiceCallRecordMapper.xml b/src/main/resources/mapper/MidVoiceCallRecordMapper.xml
index 6be0d39..0032322 100644
--- a/src/main/resources/mapper/MidVoiceCallRecordMapper.xml
+++ b/src/main/resources/mapper/MidVoiceCallRecordMapper.xml
@@ -48,11 +48,19 @@
 
     <!-- 根据通话记录ID查询（防止重复） -->
     <select id="selectByCallRecordId" resultMap="BaseResultMap">
-        SELECT * FROM mid_voice_call_record 
+        SELECT * FROM mid_voice_call_record
         WHERE call_record_id = #{callRecordId}
         LIMIT 1
     </select>
 
+    <!-- 批量查询某设备在时间范围内已存在的call_record_id（防重复，一次查询代替N次） -->
+    <select id="selectExistingCallRecordIds" resultType="java.lang.String">
+        SELECT call_record_id FROM mid_voice_call_record
+        WHERE device_no = #{deviceNo}
+        AND call_start_time >= TO_TIMESTAMP(#{startTime}, 'YYYY-MM-DD HH24:MI:SS')
+        AND call_start_time &lt;= TO_TIMESTAMP(#{endTime}, 'YYYY-MM-DD HH24:MI:SS')
+    </select>
+
     <!-- 根据设备编码查询 -->
     <select id="selectByDeviceNo" resultMap="BaseResultMap">
         SELECT * FROM mid_voice_call_record