diff --git a/backend/services/mining-admin-service/prisma/migrations/20260113000000_remove_cdc_foreign_keys/migration.sql b/backend/services/mining-admin-service/prisma/migrations/20260113000000_use_prisma_relation_mode/migration.sql
similarity index 53%
rename from backend/services/mining-admin-service/prisma/migrations/20260113000000_remove_cdc_foreign_keys/migration.sql
rename to backend/services/mining-admin-service/prisma/migrations/20260113000000_use_prisma_relation_mode/migration.sql
index 209cce74..fa74406f 100644
--- a/backend/services/mining-admin-service/prisma/migrations/20260113000000_remove_cdc_foreign_keys/migration.sql
+++ b/backend/services/mining-admin-service/prisma/migrations/20260113000000_use_prisma_relation_mode/migration.sql
@@ -1,7 +1,9 @@
 -- =============================================================================
--- 移除 CDC 同步表的外键约束
+-- 切换到 Prisma relationMode = "prisma"
+-- 移除数据库层的外键约束，改由 Prisma Client 在应用层模拟外键关系
+--
 -- 原因：CDC 事件异步到达，顺序不可控，子表记录可能在父表记录之前到达
--- 参考：https://estuary.dev/blog/cdc-done-correctly/
+-- 参考：https://www.prisma.io/docs/orm/prisma-schema/data-model/relations/relation-mode
 -- =============================================================================
 
 -- 移除 synced_contribution_accounts 表的外键约束
@@ -19,3 +21,16 @@ DROP CONSTRAINT IF EXISTS "synced_mining_accounts_accountSequence_fkey";
 -- 移除 synced_trading_accounts 表的外键约束
 ALTER TABLE "synced_trading_accounts"
 DROP CONSTRAINT IF EXISTS "synced_trading_accounts_accountSequence_fkey";
+
+-- 为 accountSequence 字段添加索引以优化 JOIN 性能（如果不存在）
+CREATE INDEX IF NOT EXISTS "synced_contribution_accounts_accountSequence_idx"
+ON "synced_contribution_accounts"("accountSequence");
+
+CREATE INDEX IF NOT EXISTS "synced_referrals_accountSequence_idx"
+ON "synced_referrals"("accountSequence");
+
+CREATE INDEX IF NOT EXISTS "synced_mining_accounts_accountSequence_idx"
+ON "synced_mining_accounts"("accountSequence");
+
+CREATE INDEX IF NOT EXISTS "synced_trading_accounts_accountSequence_idx"
+ON "synced_trading_accounts"("accountSequence");
diff --git a/backend/services/mining-admin-service/prisma/schema.prisma b/backend/services/mining-admin-service/prisma/schema.prisma
index d0c0a3fe..a8674360 100644
--- a/backend/services/mining-admin-service/prisma/schema.prisma
+++ b/backend/services/mining-admin-service/prisma/schema.prisma
@@ -3,8 +3,9 @@ generator client {
 }
 
 datasource db {
-  provider = "postgresql"
-  url      = env("DATABASE_URL")
+  provider     = "postgresql"
+  url          = env("DATABASE_URL")
+  relationMode = "prisma"  // CDC场景：Prisma层模拟外键关系，数据库不创建FK约束
 }
 
 // =============================================================================
@@ -163,8 +164,11 @@ model SyncedUser {
   syncedAt          DateTime @default(now())
   updatedAt         DateTime @updatedAt
 
-  // CDC 同步表不设置外键约束，因为事件到达顺序不可控
-  // 使用 accountSequence 作为逻辑关联键，查询时用 LEFT JOIN
+  // 关联同步表
+  contributionAccount SyncedContributionAccount?
+  miningAccount       SyncedMiningAccount?
+  tradingAccount      SyncedTradingAccount?
+  referral            SyncedReferral?
 
   @@index([phone])
   @@index([status])
@@ -179,7 +183,7 @@ model SyncedUser {
 
 model SyncedContributionAccount {
   id                      String   @id @default(uuid())
-  accountSequence         String   @unique  // 逻辑关联 SyncedUser.accountSequence，无外键约束
+  accountSequence         String   @unique
   personalContribution    Decimal  @db.Decimal(30, 8) @default(0)
   teamLevelContribution   Decimal  @db.Decimal(30, 8) @default(0)
   teamBonusContribution   Decimal  @db.Decimal(30, 8) @default(0)
@@ -192,6 +196,8 @@ model SyncedContributionAccount {
   syncedAt                DateTime @default(now())
   updatedAt               DateTime @updatedAt
 
+  user                    SyncedUser @relation(fields: [accountSequence], references: [accountSequence])
+
   @@map("synced_contribution_accounts")
 }
 
@@ -201,7 +207,7 @@ model SyncedContributionAccount {
 
 model SyncedReferral {
   id                      String   @id @default(uuid())
-  accountSequence         String   @unique  // 逻辑关联 SyncedUser.accountSequence，无外键约束
+  accountSequence         String   @unique
   referrerAccountSequence String?  // 推荐人账户序列号
   referrerUserId          BigInt?  // 1.0 的 referrer_id
   originalUserId          BigInt?  // 1.0 的 user_id
@@ -210,6 +216,8 @@ model SyncedReferral {
   syncedAt                DateTime @default(now())
   updatedAt               DateTime @updatedAt
 
+  user                    SyncedUser @relation(fields: [accountSequence], references: [accountSequence])
+
   @@index([referrerAccountSequence])
   @@index([depth])
   @@map("synced_referrals")
@@ -301,7 +309,7 @@ model SyncedNetworkProgress {
 
 model SyncedMiningAccount {
   id                String   @id @default(uuid())
-  accountSequence   String   @unique  // 逻辑关联 SyncedUser.accountSequence，无外键约束
+  accountSequence   String   @unique
   totalMined        Decimal  @db.Decimal(30, 8) @default(0)
   availableBalance  Decimal  @db.Decimal(30, 8) @default(0)
   frozenBalance     Decimal  @db.Decimal(30, 8) @default(0)
@@ -309,6 +317,8 @@ model SyncedMiningAccount {
   syncedAt          DateTime @default(now())
   updatedAt         DateTime @updatedAt
 
+  user              SyncedUser @relation(fields: [accountSequence], references: [accountSequence])
+
   @@map("synced_mining_accounts")
 }
 
@@ -318,7 +328,7 @@ model SyncedMiningAccount {
 
 model SyncedTradingAccount {
   id              String   @id @default(uuid())
-  accountSequence String   @unique  // 逻辑关联 SyncedUser.accountSequence，无外键约束
+  accountSequence String   @unique
   shareBalance    Decimal  @db.Decimal(30, 8) @default(0)
   cashBalance     Decimal  @db.Decimal(30, 8) @default(0)
   frozenShares    Decimal  @db.Decimal(30, 8) @default(0)
@@ -328,6 +338,8 @@ model SyncedTradingAccount {
   syncedAt        DateTime @default(now())
   updatedAt       DateTime @updatedAt
 
+  user            SyncedUser @relation(fields: [accountSequence], references: [accountSequence])
+
   @@map("synced_trading_accounts")
 }