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 0823152b..894ec232 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
@@ -271,7 +271,7 @@ export class AuthorizationApplicationService {
    *
    * 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）
+   * - 同一个省份只允许授权给一个账户（按省份唯一）
    */
   async grantProvinceCompany(command: GrantProvinceCompanyCommand): Promise<void> {
     const userId = UserId.create(command.userId, command.accountSequence)
@@ -299,11 +299,11 @@ export class AuthorizationApplicationService {
       )
     }
 
-    // 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) {
+    // 3. 检查该省份是否已有省区域授权（同一省份只能授权给一个账户）
+    const existingProvinceRegion = await this.authorizationRepository.findProvinceCompanyByRegion(command.provinceCode)
+    if (existingProvinceRegion) {
       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`,
+        `省份「${command.provinceName}」已有省区域角色授权给用户 ${existingProvinceRegion.userId.accountSequence}，不能重复授权`,
       )
     }
 
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 5669d781..548fd7fa 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
@@ -96,9 +96,4 @@ 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 1096e1d7..d4069a58 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
@@ -399,16 +399,6 @@ 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),