diff --git a/ruoyi-modules/ruoyi-system/src/main/java/org/dromara/system/service/impl/SysDeptServiceImpl.java b/ruoyi-modules/ruoyi-system/src/main/java/org/dromara/system/service/impl/SysDeptServiceImpl.java
index bbda484..72ff40b 100644
--- a/ruoyi-modules/ruoyi-system/src/main/java/org/dromara/system/service/impl/SysDeptServiceImpl.java
+++ b/ruoyi-modules/ruoyi-system/src/main/java/org/dromara/system/service/impl/SysDeptServiceImpl.java
@@ -161,9 +161,12 @@ public class SysDeptServiceImpl implements ISysDeptService {
      * @param deptId 部门ID
      * @return 部门信息
      */
-    @Cacheable(cacheNames = CacheNames.SYS_DEPT, key = "#deptId")
+    @Cacheable(cacheNames = CacheNames.SYS_DEPT, key = "#deptId", condition = "#deptId != null")
     @Override
     public SysDeptVo selectDeptById(Long deptId) {
+        if (ObjectUtil.isNull(deptId)) {
+            return null;
+        }
         SysDeptVo dept = baseMapper.selectVoById(deptId);
         if (ObjectUtil.isNull(dept)) {
             return null;
@@ -198,9 +201,11 @@ public class SysDeptServiceImpl implements ISysDeptService {
     public String selectDeptNameByIds(String deptIds) {
         List<String> list = new ArrayList<>();
         for (Long id : StringUtils.splitTo(deptIds, Convert::toLong)) {
-            SysDeptVo vo = SpringUtils.getAopProxy(this).selectDeptById(id);
-            if (ObjectUtil.isNotNull(vo)) {
-                list.add(vo.getDeptName());
+            if (ObjectUtil.isNotNull(id)) {
+                SysDeptVo vo = SpringUtils.getAopProxy(this).selectDeptById(id);
+                if (ObjectUtil.isNotNull(vo)) {
+                    list.add(vo.getDeptName());
+                }
             }
         }
         return String.join(StringUtils.SEPARATOR, list);