diff --git a/src/main/java/com/ai/da/service/impl/ClassificationServiceImpl.java b/src/main/java/com/ai/da/service/impl/ClassificationServiceImpl.java
index f41938be..2da856eb 100644
--- a/src/main/java/com/ai/da/service/impl/ClassificationServiceImpl.java
+++ b/src/main/java/com/ai/da/service/impl/ClassificationServiceImpl.java
@@ -236,11 +236,17 @@ public class ClassificationServiceImpl implements ClassificationService {
         if (CollectionUtil.isNotEmpty(addIdList)) {
             for (Long libraryId : classificationDTO.getLibraryIdList()) {
                 for (Long classificationId : addIdList) {
-                    ClassificationRelLibrary classificationRelLibrary = new ClassificationRelLibrary();
-                    classificationRelLibrary.setClassificationId(classificationId);
-                    classificationRelLibrary.setLibraryId(libraryId);
-                    classificationRelLibrary.setCreateTime(LocalDateTime.now());
-                    classificationRelLibraryMapper.insert(classificationRelLibrary);
+                    QueryWrapper<ClassificationRelLibrary> qw = new QueryWrapper<>();
+                    qw.lambda().eq(ClassificationRelLibrary::getLibraryId, libraryId);
+                    qw.lambda().eq(ClassificationRelLibrary::getClassificationId, classificationId);
+                    List<ClassificationRelLibrary> exist = classificationRelLibraryMapper.selectList(qw);
+                    if (CollectionUtil.isEmpty(exist)) {
+                        ClassificationRelLibrary classificationRelLibrary = new ClassificationRelLibrary();
+                        classificationRelLibrary.setClassificationId(classificationId);
+                        classificationRelLibrary.setLibraryId(libraryId);
+                        classificationRelLibrary.setCreateTime(LocalDateTime.now());
+                        classificationRelLibraryMapper.insert(classificationRelLibrary);
+                    }
                 }
             }
         }