diff --git a/backend/services/authorization-service/src/application/services/authorization-application.service.ts b/backend/services/authorization-service/src/application/services/authorization-application.service.ts
index f77b1623..0823152b 100644
--- a/backend/services/authorization-service/src/application/services/authorization-application.service.ts
+++ b/backend/services/authorization-service/src/application/services/authorization-application.service.ts
@@ -268,27 +268,46 @@ export class AuthorizationApplicationService {
 
   /**
    * 管理员授权正式省公司（省区域）
-   * 需要验证团队内唯一性：同一推荐链上不能有重复的相同省份授权
+   *
+   * 业务规则：
+   * - 同一个用户不能同时拥有省区域和市区域两种身份
+   * - 整个系统中只允许一个省区域角色被授权（全局唯一）
    */
   async grantProvinceCompany(command: GrantProvinceCompanyCommand): Promise<void> {
     const userId = UserId.create(command.userId, command.accountSequence)
     const adminId = AdminUserId.create(command.adminId, command.adminAccountSequence)
-    const regionCode = RegionCode.create(command.provinceCode)
 
-    // 1. 验证团队内唯一性（同一推荐链上不能有重复的相同省份授权）
-    const validation = await this.validatorService.validateAuthorizationRequest(
-      userId,
-      RoleType.PROVINCE_COMPANY,
-      regionCode,
-      this.referralRepository,
-      this.authorizationRepository,
+    // 1. 检查用户是否已有市区域授权（省区域和市区域互斥）
+    const existingCityCompany = await this.authorizationRepository.findByAccountSequenceAndRoleType(
+      command.accountSequence,
+      RoleType.CITY_COMPANY,
     )
-
-    if (!validation.isValid) {
-      throw new ApplicationError(validation.errorMessage!)
+    if (existingCityCompany && existingCityCompany.status !== AuthorizationStatus.REVOKED) {
+      throw new ApplicationError(
+        `用户 ${command.accountSequence} 已拥有市区域角色「${existingCityCompany.regionName}」，不能同时拥有省区域角色`,
+      )
     }
 
-    // 2. 创建授权
+    // 2. 检查用户是否已有省区域授权（一个用户只能有一个省区域）
+    const existingProvinceCompany = await this.authorizationRepository.findByAccountSequenceAndRoleType(
+      command.accountSequence,
+      RoleType.PROVINCE_COMPANY,
+    )
+    if (existingProvinceCompany && existingProvinceCompany.status !== AuthorizationStatus.REVOKED) {
+      throw new ApplicationError(
+        `用户 ${command.accountSequence} 已拥有省区域角色「${existingProvinceCompany.regionName}」，不能重复授权`,
+      )
+    }
+
+    // 3. 检查系统中是否已有省区域授权（整个系统全局唯一）
+    const existingAnyProvince = await this.authorizationRepository.findAnyProvinceCompany()
+    if (existingAnyProvince) {
+      throw new ApplicationError(
+        `系统中已有省区域角色授权给用户 ${existingAnyProvince.userId.accountSequence}（${existingAnyProvince.regionName}），整个系统只允许一个省区域角色`,
+      )
+    }
+
+    // 4. 创建授权
     const authorization = AuthorizationRole.createProvinceCompany({
       userId,
       provinceCode: command.provinceCode,
diff --git a/backend/services/authorization-service/src/domain/repositories/authorization-role.repository.ts b/backend/services/authorization-service/src/domain/repositories/authorization-role.repository.ts
index 548fd7fa..5669d781 100644
--- a/backend/services/authorization-service/src/domain/repositories/authorization-role.repository.ts
+++ b/backend/services/authorization-service/src/domain/repositories/authorization-role.repository.ts
@@ -96,4 +96,9 @@ export interface IAuthorizationRoleRepository {
    * 根据社区名称查找社区授权（用于社区名称全局唯一性校验）
    */
   findCommunityByName(communityName: string): Promise<AuthorizationRole | null>
+  /**
+   * 查找系统中任何已授权的省区域角色（用于省区域全局唯一性校验）
+   * 整个系统只允许一个省区域角色被授权
+   */
+  findAnyProvinceCompany(): Promise<AuthorizationRole | null>
 }
diff --git a/backend/services/authorization-service/src/infrastructure/persistence/repositories/authorization-role.repository.impl.ts b/backend/services/authorization-service/src/infrastructure/persistence/repositories/authorization-role.repository.impl.ts
index d4069a58..1096e1d7 100644
--- a/backend/services/authorization-service/src/infrastructure/persistence/repositories/authorization-role.repository.impl.ts
+++ b/backend/services/authorization-service/src/infrastructure/persistence/repositories/authorization-role.repository.impl.ts
@@ -399,6 +399,16 @@ export class AuthorizationRoleRepositoryImpl implements IAuthorizationRoleReposi
     return record ? this.toDomain(record) : null
   }
 
+  async findAnyProvinceCompany(): Promise<AuthorizationRole | null> {
+    const record = await this.prisma.authorizationRole.findFirst({
+      where: {
+        roleType: RoleType.PROVINCE_COMPANY,
+        status: AuthorizationStatus.AUTHORIZED,
+      },
+    })
+    return record ? this.toDomain(record) : null
+  }
+
   private toDomain(record: any): AuthorizationRole {
     const props: AuthorizationRoleProps = {
       authorizationId: AuthorizationId.create(record.id),