diff --git a/backend/services/mining-admin-service/src/application/services/system-accounts.service.ts b/backend/services/mining-admin-service/src/application/services/system-accounts.service.ts
index c6dc494e..8ff2abcf 100644
--- a/backend/services/mining-admin-service/src/application/services/system-accounts.service.ts
+++ b/backend/services/mining-admin-service/src/application/services/system-accounts.service.ts
@@ -326,9 +326,10 @@ export class SystemAccountsService {
     page: number = 1,
     pageSize: number = 20,
   ) {
+    // Prisma 查询 null 值需要用 { equals: null }
     const whereClause = regionCode
       ? { accountType, regionCode }
-      : { accountType, regionCode: null };
+      : { accountType, regionCode: { equals: null } };
 
     const [records, total] = await Promise.all([
       this.prisma.syncedSystemContributionRecord.findMany({
@@ -380,7 +381,7 @@ export class SystemAccountsService {
 
     const whereClause = regionCode
       ? { accountType, regionCode }
-      : { accountType, regionCode: null };
+      : { accountType, regionCode: { equals: null } };
 
     // 获取明细记录统计
     const recordStats = await this.prisma.syncedSystemContributionRecord.aggregate({