diff --git a/safety-cedu-service/src/main/java/org/qinan/cedu/service/impl/CourseManagementServiceImpl.java b/safety-cedu-service/src/main/java/org/qinan/cedu/service/impl/CourseManagementServiceImpl.java
index 95bc1eab..a74dfe72 100644
--- a/safety-cedu-service/src/main/java/org/qinan/cedu/service/impl/CourseManagementServiceImpl.java
+++ b/safety-cedu-service/src/main/java/org/qinan/cedu/service/impl/CourseManagementServiceImpl.java
@@ -60,17 +60,19 @@ public class CourseManagementServiceImpl extends ServiceImpl<CourseManagementMap
                 .orderByDesc(CourseManagementDO::getCreateTime)
                 .page(new Page<>(query.getCurrent(), query.getSize()));
         IPage<CourseManagementVO> convert = page.convert(courseManagementConvertor::convertEToVo);
-        Map<Long, Integer> collectMap = classCourseMapper.selectList(new LambdaQueryWrapper<ClassCourseDO>()
-                        .in(ClassCourseDO::getCourseId, convert.getRecords().stream().map(CourseManagementVO::getId).collect(Collectors.toList())))
-                .stream().map(ClassCourseDO::getCourseId).distinct().collect(Collectors.toMap(v -> v, v -> 1));
-        convert.getRecords().forEach(vo -> {
-            vo.setCourseRelCoursewareVOList(courseRelCoursewareConvertor.convertEListToVoList(
-                    courseRelCoursewareMapper.selectList(new LambdaQueryWrapper<CourseRelCoursewareDO>()
-                            .eq(CourseRelCoursewareDO::getCourseId, vo.getId())
-                            .orderByAsc(CourseRelCoursewareDO::getSort))
-            ));
-            vo.setUsed(Math.toIntExact(collectMap.getOrDefault(Long.valueOf(vo.getId()), 0)));
-        });
+        if (convert.getRecords() != null && convert.getRecords().size() > 0) {
+            Map<Long, Integer> collectMap = classCourseMapper.selectList(new LambdaQueryWrapper<ClassCourseDO>()
+                            .in(ClassCourseDO::getCourseId, convert.getRecords().stream().map(CourseManagementVO::getId).collect(Collectors.toList())))
+                    .stream().map(ClassCourseDO::getCourseId).distinct().collect(Collectors.toMap(v -> v, v -> 1));
+            convert.getRecords().forEach(vo -> {
+                vo.setCourseRelCoursewareVOList(courseRelCoursewareConvertor.convertEListToVoList(
+                        courseRelCoursewareMapper.selectList(new LambdaQueryWrapper<CourseRelCoursewareDO>()
+                                .eq(CourseRelCoursewareDO::getCourseId, vo.getId())
+                                .orderByAsc(CourseRelCoursewareDO::getSort))
+                ));
+                vo.setUsed(Math.toIntExact(collectMap.getOrDefault(Long.valueOf(vo.getId()), 0)));
+            });
+        }
         return convert;
     }