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 3aba403b..8bfab135 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
@@ -383,8 +383,12 @@ export class SystemAccountsService {
    */
   async getSystemAccountContributionStats(accountType: string, regionCode: string | null) {
     // 获取算力账户信息
-    const contribution = await this.prisma.syncedSystemContribution.findUnique({
-      where: { accountType_regionCode: { accountType, regionCode } },
+    // 使用 findFirst 替代 findUnique，因为 regionCode 可以为 null
+    const contribution = await this.prisma.syncedSystemContribution.findFirst({
+      where: {
+        accountType,
+        regionCode: regionCode === null ? { equals: null } : regionCode,
+      },
     });
 
     const whereClause = regionCode
diff --git a/backend/services/mining-admin-service/src/infrastructure/kafka/cdc-sync.service.ts b/backend/services/mining-admin-service/src/infrastructure/kafka/cdc-sync.service.ts
index c29f58dc..d3babc9a 100644
--- a/backend/services/mining-admin-service/src/infrastructure/kafka/cdc-sync.service.ts
+++ b/backend/services/mining-admin-service/src/infrastructure/kafka/cdc-sync.service.ts
@@ -540,20 +540,37 @@ export class CdcSyncService implements OnModuleInit {
 
   private async handleSystemContributionUpdated(event: ServiceEvent, tx: TransactionClient): Promise<void> {
     const { payload } = event;
-    await tx.syncedSystemContribution.upsert({
-      where: { accountType: payload.accountType },
-      create: {
-        accountType: payload.accountType,
-        name: payload.name,
-        contributionBalance: payload.contributionBalance || 0,
-        contributionNeverExpires: payload.contributionNeverExpires || false,
-      },
-      update: {
-        name: payload.name,
-        contributionBalance: payload.contributionBalance,
-        contributionNeverExpires: payload.contributionNeverExpires,
+    const accountType = payload.accountType;
+    const regionCode = payload.regionCode || null;
+
+    // 使用 findFirst + create/update 替代 upsert，因为 regionCode 可以为 null
+    const existing = await tx.syncedSystemContribution.findFirst({
+      where: {
+        accountType,
+        regionCode: regionCode === null ? { equals: null } : regionCode,
       },
     });
+
+    if (existing) {
+      await tx.syncedSystemContribution.update({
+        where: { id: existing.id },
+        data: {
+          name: payload.name,
+          contributionBalance: payload.contributionBalance,
+          contributionNeverExpires: payload.contributionNeverExpires,
+        },
+      });
+    } else {
+      await tx.syncedSystemContribution.create({
+        data: {
+          accountType,
+          regionCode,
+          name: payload.name,
+          contributionBalance: payload.contributionBalance || 0,
+          contributionNeverExpires: payload.contributionNeverExpires || false,
+        },
+      });
+    }
   }
 
   /**
@@ -567,23 +584,33 @@ export class CdcSyncService implements OnModuleInit {
     const accountType = payload.accountType; // OPERATION / PROVINCE / CITY / HEADQUARTERS
     const regionCode = payload.regionCode || null;
 
-    // 使用 accountType + regionCode 作为复合唯一键
-    await tx.syncedSystemContribution.upsert({
+    // 使用 findFirst + create/update 替代 upsert，因为 regionCode 可以为 null
+    const existing = await tx.syncedSystemContribution.findFirst({
       where: {
-        accountType_regionCode: { accountType, regionCode },
-      },
-      create: {
         accountType,
-        regionCode,
-        name: payload.name,
-        contributionBalance: payload.contributionBalance || 0,
-        contributionNeverExpires: true, // 系统账户算力永不过期
-      },
-      update: {
-        name: payload.name,
-        contributionBalance: payload.contributionBalance,
+        regionCode: regionCode === null ? { equals: null } : regionCode,
       },
     });
+
+    if (existing) {
+      await tx.syncedSystemContribution.update({
+        where: { id: existing.id },
+        data: {
+          name: payload.name,
+          contributionBalance: payload.contributionBalance,
+        },
+      });
+    } else {
+      await tx.syncedSystemContribution.create({
+        data: {
+          accountType,
+          regionCode,
+          name: payload.name,
+          contributionBalance: payload.contributionBalance || 0,
+          contributionNeverExpires: true, // 系统账户算力永不过期
+        },
+      });
+    }
   }
 
   /**
diff --git a/backend/services/mining-service/src/api/controllers/admin.controller.ts b/backend/services/mining-service/src/api/controllers/admin.controller.ts
index b102e165..38a61082 100644
--- a/backend/services/mining-service/src/api/controllers/admin.controller.ts
+++ b/backend/services/mining-service/src/api/controllers/admin.controller.ts
@@ -199,12 +199,12 @@ export class AdminController {
     const skip = (pageNum - 1) * pageSizeNum;
 
     // 先通过 accountType + regionCode 查找系统账户
-    const account = await this.prisma.systemMiningAccount.findUnique({
+    // 使用 findFirst 替代 findUnique，因为 regionCode 可以为 null
+    const regionCodeValue = regionCode || null;
+    const account = await this.prisma.systemMiningAccount.findFirst({
       where: {
-        accountType_regionCode: {
-          accountType,
-          regionCode: regionCode || null,
-        },
+        accountType,
+        regionCode: regionCodeValue === null ? { equals: null } : regionCodeValue,
       },
     });
 
@@ -215,7 +215,7 @@ export class AdminController {
         page: pageNum,
         pageSize: pageSizeNum,
         accountType,
-        regionCode: regionCode || null,
+        regionCode: regionCodeValue,
       };
     }
 
@@ -247,7 +247,7 @@ export class AdminController {
       page: pageNum,
       pageSize: pageSizeNum,
       accountType,
-      regionCode: regionCode || null,
+      regionCode: regionCodeValue,
     };
   }
 
@@ -269,12 +269,12 @@ export class AdminController {
     const skip = (pageNum - 1) * pageSizeNum;
 
     // 先通过 accountType + regionCode 查找系统账户
-    const account = await this.prisma.systemMiningAccount.findUnique({
+    // 使用 findFirst 替代 findUnique，因为 regionCode 可以为 null
+    const regionCodeValue = regionCode || null;
+    const account = await this.prisma.systemMiningAccount.findFirst({
       where: {
-        accountType_regionCode: {
-          accountType,
-          regionCode: regionCode || null,
-        },
+        accountType,
+        regionCode: regionCodeValue === null ? { equals: null } : regionCodeValue,
       },
     });
 
@@ -285,7 +285,7 @@ export class AdminController {
         page: pageNum,
         pageSize: pageSizeNum,
         accountType,
-        regionCode: regionCode || null,
+        regionCode: regionCodeValue,
       };
     }
 
@@ -305,7 +305,7 @@ export class AdminController {
       transactions: transactions.map((tx) => ({
         id: tx.id,
         accountType,
-        regionCode: regionCode || null,
+        regionCode: regionCodeValue,
         type: tx.type,
         amount: tx.amount.toString(),
         balanceBefore: tx.balanceBefore.toString(),
@@ -319,7 +319,7 @@ export class AdminController {
       page: pageNum,
       pageSize: pageSizeNum,
       accountType,
-      regionCode: regionCode || null,
+      regionCode: regionCodeValue,
     };
   }
 
diff --git a/backend/services/mining-service/src/application/services/mining-distribution.service.ts b/backend/services/mining-service/src/application/services/mining-distribution.service.ts
index f409f723..be197f12 100644
--- a/backend/services/mining-service/src/application/services/mining-distribution.service.ts
+++ b/backend/services/mining-service/src/application/services/mining-distribution.service.ts
@@ -531,7 +531,8 @@ export class MiningDistributionService {
     let systemParticipantCount = 0;
     let pendingParticipantCount = 0;
     const systemRedisData: Array<{
-      accountType: string;  // 改为字符串支持组合键
+      accountType: string;
+      regionCode: string | null;
       reward: ShareAmount;
       contribution: ShareAmount;
     }> = [];
diff --git a/backend/services/mining-service/src/infrastructure/persistence/repositories/system-mining-account.repository.ts b/backend/services/mining-service/src/infrastructure/persistence/repositories/system-mining-account.repository.ts
index 805a9413..67ba2ebb 100644
--- a/backend/services/mining-service/src/infrastructure/persistence/repositories/system-mining-account.repository.ts
+++ b/backend/services/mining-service/src/infrastructure/persistence/repositories/system-mining-account.repository.ts
@@ -24,9 +24,11 @@ export class SystemMiningAccountRepository {
     accountType: SystemAccountType,
     regionCode: string | null,
   ): Promise<SystemMiningAccountSnapshot | null> {
-    const record = await this.prisma.systemMiningAccount.findUnique({
+    // 使用 findFirst 替代 findUnique，因为 regionCode 可以为 null
+    const record = await this.prisma.systemMiningAccount.findFirst({
       where: {
-        accountType_regionCode: { accountType, regionCode },
+        accountType,
+        regionCode: regionCode === null ? { equals: null } : regionCode,
       },
     });
 
@@ -67,20 +69,26 @@ export class SystemMiningAccountRepository {
     ];
 
     for (const account of accounts) {
-      await this.prisma.systemMiningAccount.upsert({
+      // 使用 findFirst + create 替代 upsert，因为 regionCode 可以为 null
+      const existing = await this.prisma.systemMiningAccount.findFirst({
         where: {
-          accountType_regionCode: { accountType: account.accountType, regionCode: null },
-        },
-        create: {
           accountType: account.accountType,
-          regionCode: null,
-          name: account.name,
-          totalMined: 0,
-          availableBalance: 0,
-          totalContribution: 0,
+          regionCode: { equals: null },
         },
-        update: {},
       });
+
+      if (!existing) {
+        await this.prisma.systemMiningAccount.create({
+          data: {
+            accountType: account.accountType,
+            regionCode: null,
+            name: account.name,
+            totalMined: 0,
+            availableBalance: 0,
+            totalContribution: 0,
+          },
+        });
+      }
     }
   }
 
@@ -93,22 +101,33 @@ export class SystemMiningAccountRepository {
     name: string,
     contribution: ShareAmount,
   ): Promise<void> {
-    await this.prisma.systemMiningAccount.upsert({
+    // 使用 findFirst + create/update 替代 upsert，因为 regionCode 可以为 null
+    const existing = await this.prisma.systemMiningAccount.findFirst({
       where: {
-        accountType_regionCode: { accountType, regionCode },
-      },
-      create: {
         accountType,
-        regionCode,
-        name,
-        totalContribution: contribution.value,
-        lastSyncedAt: new Date(),
-      },
-      update: {
-        totalContribution: contribution.value,
-        lastSyncedAt: new Date(),
+        regionCode: regionCode === null ? { equals: null } : regionCode,
       },
     });
+
+    if (existing) {
+      await this.prisma.systemMiningAccount.update({
+        where: { id: existing.id },
+        data: {
+          totalContribution: contribution.value,
+          lastSyncedAt: new Date(),
+        },
+      });
+    } else {
+      await this.prisma.systemMiningAccount.create({
+        data: {
+          accountType,
+          regionCode,
+          name,
+          totalContribution: contribution.value,
+          lastSyncedAt: new Date(),
+        },
+      });
+    }
   }
 
   async getTotalContribution(): Promise<ShareAmount> {
@@ -130,9 +149,11 @@ export class SystemMiningAccountRepository {
     tx?: TransactionClient,
   ): Promise<void> {
     const executeInTx = async (client: TransactionClient) => {
-      const account = await client.systemMiningAccount.findUnique({
+      // 使用 findFirst 替代 findUnique，因为 regionCode 可以为 null
+      const account = await client.systemMiningAccount.findFirst({
         where: {
-          accountType_regionCode: { accountType, regionCode },
+          accountType,
+          regionCode: regionCode === null ? { equals: null } : regionCode,
         },
       });
 
@@ -180,9 +201,11 @@ export class SystemMiningAccountRepository {
     secondDistribution: ShareAmount,
     minedAmount: ShareAmount,
   ): Promise<void> {
-    const account = await this.prisma.systemMiningAccount.findUnique({
+    // 使用 findFirst 替代 findUnique，因为 regionCode 可以为 null
+    const account = await this.prisma.systemMiningAccount.findFirst({
       where: {
-        accountType_regionCode: { accountType, regionCode },
+        accountType,
+        regionCode: regionCode === null ? { equals: null } : regionCode,
       },
     });