diff --git a/backend/src/main/kotlin/com/wrbug/polymarketbot/service/system/ProcessedTradeCleanupService.kt b/backend/src/main/kotlin/com/wrbug/polymarketbot/service/system/ProcessedTradeCleanupService.kt
new file mode 100644
index 0000000..ea52491
--- /dev/null
+++ b/backend/src/main/kotlin/com/wrbug/polymarketbot/service/system/ProcessedTradeCleanupService.kt
@@ -0,0 +1,46 @@
+package com.wrbug.polymarketbot.service.system
+
+import com.wrbug.polymarketbot.repository.ProcessedTradeRepository
+import org.slf4j.LoggerFactory
+import org.springframework.scheduling.annotation.Scheduled
+import org.springframework.stereotype.Service
+
+/**
+ * 已处理交易清理服务
+ * 定期清理过期的去重记录
+ */
+@Service
+class ProcessedTradeCleanupService(
+    private val processedTradeRepository: ProcessedTradeRepository
+) {
+
+    companion object {
+        private val logger = LoggerFactory.getLogger(ProcessedTradeCleanupService::class.java)
+
+        // 保留时间：1小时（3600000毫秒）
+        // 说明：重复订单通常10秒后就不会再出现，保留10分钟是为了安全起见
+        private const val RETENTION_MS = 600_000L
+
+        // 定时清理间隔：10分钟（600000毫秒）
+        private const val CLEANUP_INTERVAL_MS = 600_000L
+    }
+
+    /**
+     * 定时清理过期记录
+     * 每10分钟执行一次
+     */
+    @Scheduled(fixedDelay = CLEANUP_INTERVAL_MS)
+    fun cleanupExpiredProcessedTrades() {
+        try {
+            val expireTime = System.currentTimeMillis() - RETENTION_MS
+            val deletedCount = processedTradeRepository.deleteByProcessedAtBefore(expireTime)
+
+            if (deletedCount > 0) {
+                logger.info("清理过期已处理交易记录: deletedCount=$deletedCount, expireTime=$expireTime")
+            }
+        } catch (e: Exception) {
+            logger.error("清理过期已处理交易记录失败", e)
+        }
+    }
+}
+