diff --git a/src/main/java/top/suyiiyii/sims/mapper/MpRoleMapper.java b/src/main/java/top/suyiiyii/sims/mapper/MpRoleMapper.java
new file mode 100644
index 0000000..70d3bd4
--- /dev/null
+++ b/src/main/java/top/suyiiyii/sims/mapper/MpRoleMapper.java
@@ -0,0 +1,7 @@
+package top.suyiiyii.sims.mapper;
+
+import com.baomidou.mybatisplus.core.mapper.BaseMapper;
+import top.suyiiyii.sims.entity.Role;
+
+public interface MpRoleMapper extends BaseMapper<Role> {
+}
diff --git a/src/main/java/top/suyiiyii/sims/mapper/MpUserRoleMapper.java b/src/main/java/top/suyiiyii/sims/mapper/MpUserRoleMapper.java
new file mode 100644
index 0000000..759242d
--- /dev/null
+++ b/src/main/java/top/suyiiyii/sims/mapper/MpUserRoleMapper.java
@@ -0,0 +1,7 @@
+package top.suyiiyii.sims.mapper;
+
+import com.baomidou.mybatisplus.core.mapper.BaseMapper;
+import top.suyiiyii.sims.entity.UserRole;
+
+public interface MpUserRoleMapper extends BaseMapper<UserRole> {
+}
diff --git a/src/main/java/top/suyiiyii/sims/service/RbacService.java b/src/main/java/top/suyiiyii/sims/service/RbacService.java
new file mode 100644
index 0000000..8d56220
--- /dev/null
+++ b/src/main/java/top/suyiiyii/sims/service/RbacService.java
@@ -0,0 +1,41 @@
+package top.suyiiyii.sims.service;
+
+import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+import top.suyiiyii.sims.entity.Role;
+import top.suyiiyii.sims.entity.UserRole;
+import top.suyiiyii.sims.mapper.MpRoleMapper;
+import top.suyiiyii.sims.mapper.MpUserMapper;
+import top.suyiiyii.sims.mapper.MpUserRoleMapper;
+
+import java.util.List;
+
+@Slf4j
+@Service
+public class RbacService {
+
+    @Autowired
+    MpUserMapper userMapper;
+
+    @Autowired
+    MpUserRoleMapper userRoleMapper;
+
+    @Autowired
+    MpRoleMapper roleMapper;
+
+    /**
+     * 根据用户id获取用户的角色
+     *
+     * @param userId 用户id
+     * @return 用户的角色列表
+     */
+    public List<Role> getRolesByUserId(int userId) {
+        // 根据用户id获取用户的角色id，使用mp的条件构造器
+        List<UserRole> userRoles = userRoleMapper.selectList(new QueryWrapper<UserRole>().eq("user_id", userId));
+        // 根据角色id获取角色
+        return roleMapper.selectBatchIds(userRoles.stream().map(UserRole::getRoleId).toList());
+    }
+
+}