diff --git a/reading-platform-java/src/main/java/com/reading/platform/service/CourseLessonService.java b/reading-platform-java/src/main/java/com/reading/platform/service/CourseLessonService.java
index 3c77094..f8e9c26 100644
--- a/reading-platform-java/src/main/java/com/reading/platform/service/CourseLessonService.java
+++ b/reading-platform-java/src/main/java/com/reading/platform/service/CourseLessonService.java
@@ -21,6 +21,12 @@ public interface CourseLessonService extends IService<CourseLesson> {
      */
     CourseLesson findById(Long id);
 
+    /**
+     * 按 lessonType 查询包含该类型环节的课程 ID 列表
+     * 兼容多种存储格式：SOCIAL/SOCIETY/DOMAIN_SOCIAL、INTRODUCTION/INTRO 等
+     */
+    List<Long> findCourseIdsByLessonType(String lessonType);
+
     /**
      * 按类型查询课程环节
      */
diff --git a/reading-platform-java/src/main/java/com/reading/platform/service/impl/CourseLessonServiceImpl.java b/reading-platform-java/src/main/java/com/reading/platform/service/impl/CourseLessonServiceImpl.java
index 26d07b3..512aaca 100644
--- a/reading-platform-java/src/main/java/com/reading/platform/service/impl/CourseLessonServiceImpl.java
+++ b/reading-platform-java/src/main/java/com/reading/platform/service/impl/CourseLessonServiceImpl.java
@@ -14,7 +14,10 @@ import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
 import java.time.LocalDateTime;
+import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
+import java.util.stream.Collectors;
 
 /**
  * 课程环节服务实现类
@@ -59,6 +62,50 @@ public class CourseLessonServiceImpl extends ServiceImpl<CourseLessonMapper, Cou
         return lesson;
     }
 
+    /**
+     * 按 lessonType 查询包含该类型环节的课程 ID 列表
+     * 兼容多种存储格式：SOCIAL/SOCIETY/DOMAIN_SOCIAL、INTRODUCTION/INTRO 等
+     */
+    @Override
+    public List<Long> findCourseIdsByLessonType(String lessonType) {
+        List<String> typesToMatch = resolveLessonTypeVariants(lessonType);
+        if (typesToMatch.isEmpty()) {
+            return Collections.emptyList();
+        }
+        LambdaQueryWrapper<CourseLesson> wrapper = new LambdaQueryWrapper<CourseLesson>()
+                .select(CourseLesson::getCourseId);
+        if (typesToMatch.size() == 1) {
+            wrapper.eq(CourseLesson::getLessonType, typesToMatch.get(0));
+        } else {
+            wrapper.in(CourseLesson::getLessonType, typesToMatch);
+        }
+        return this.list(wrapper).stream()
+                .map(CourseLesson::getCourseId)
+                .distinct()
+                .collect(Collectors.toList());
+    }
+
+    /**
+     * 将前端传入的 lessonType 解析为数据库中可能存储的多种格式
+     */
+    private List<String> resolveLessonTypeVariants(String lessonType) {
+        if (lessonType == null || lessonType.isBlank()) {
+            return Collections.emptyList();
+        }
+        return switch (lessonType.toUpperCase()) {
+            case "SOCIAL" -> Arrays.asList("SOCIAL", "SOCIETY", "DOMAIN_SOCIAL");
+            case "SOCIETY" -> Arrays.asList("SOCIAL", "SOCIETY", "DOMAIN_SOCIAL");
+            case "SCIENCE" -> Arrays.asList("SCIENCE", "DOMAIN_SCIENCE");
+            case "LANGUAGE" -> Arrays.asList("LANGUAGE", "DOMAIN_LANGUAGE");
+            case "HEALTH" -> Arrays.asList("HEALTH", "DOMAIN_HEALTH");
+            case "ART" -> Arrays.asList("ART", "DOMAIN_ART");
+            case "INTRODUCTION" -> Arrays.asList("INTRODUCTION", "INTRO");
+            case "INTRO" -> Arrays.asList("INTRODUCTION", "INTRO");
+            case "COLLECTIVE" -> Collections.singletonList("COLLECTIVE");
+            default -> Collections.singletonList(lessonType);
+        };
+    }
+
     /**
      * 按类型查询课程环节
      */