diff --git a/backend/services/wallet-service/src/application/services/wallet-application.service.ts b/backend/services/wallet-service/src/application/services/wallet-application.service.ts
index 6949a303..3f200b87 100644
--- a/backend/services/wallet-service/src/application/services/wallet-application.service.ts
+++ b/backend/services/wallet-service/src/application/services/wallet-application.service.ts
@@ -2498,7 +2498,7 @@ export class WalletApplicationService {
    */
   async getUnprocessedSettlements(accountSequence: string): Promise<{
     entries: Array<{
-      id: bigint;
+      id: string;  // BigInt 转换为 string 以支持 JSON 序列化
       amount: number;
       createdAt: Date;
       memo: string | null;
@@ -2538,7 +2538,7 @@ export class WalletApplicationService {
       const payloadJson = entry.payloadJson as Record<string, unknown> | null;
       const allocationType = payloadJson?.allocationType as string | null;
       return {
-        id: entry.id,
+        id: entry.id.toString(),  // BigInt 需要转为 string 才能 JSON 序列化
         amount,
         createdAt: entry.createdAt,
         memo: entry.memo,
@@ -2708,7 +2708,7 @@ export class WalletApplicationService {
           data: {
             accountSequence: command.accountSequence,
             userId: walletRecord.userId,
-            originalLedgerEntryId: entry.id,
+            originalLedgerEntryId: BigInt(entry.id),  // 转回 BigInt 用于数据库存储
             originalAmount: entry.amount,
             deductedAmount: actualDeduct,
             deductionLedgerEntryId: ledgerEntry.id,