diff --git a/src/main/java/xyz/playedu/api/controller/backend/CourseController.java b/src/main/java/xyz/playedu/api/controller/backend/CourseController.java
index 0c3b765..2aae042 100644
--- a/src/main/java/xyz/playedu/api/controller/backend/CourseController.java
+++ b/src/main/java/xyz/playedu/api/controller/backend/CourseController.java
@@ -40,6 +40,7 @@ import xyz.playedu.api.types.paginate.PaginationResult;
 
 import java.text.ParseException;
 import java.util.*;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 
 @RestController
@@ -236,14 +237,18 @@ public class CourseController {
         List<CourseAttachment> attachments =
                 attachmentService.getAttachmentsByCourseId(course.getId());
         if (null != attachments && attachments.size() > 0) {
-            Map<Integer, String> resourceMap =
+            Map<Integer, Resource> resourceMap =
                     resourceService
                             .chunks(attachments.stream().map(CourseAttachment::getRid).toList())
                             .stream()
-                            .collect(Collectors.toMap(Resource::getId, Resource::getUrl));
+                            .collect(Collectors.toMap(Resource::getId, Function.identity()));
             attachments.forEach(
                     courseAttachment -> {
-                        courseAttachment.setUrl(resourceMap.get(courseAttachment.getRid()));
+                        Resource resource = resourceMap.get(courseAttachment.getRid());
+                        if(null != resource){
+                            courseAttachment.setUrl(resource.getUrl());
+                            courseAttachment.setExt(resource.getExtension());
+                        }
                     });
         }
 
diff --git a/src/main/java/xyz/playedu/api/domain/CourseAttachment.java b/src/main/java/xyz/playedu/api/domain/CourseAttachment.java
index b9fce75..c9113f5 100644
--- a/src/main/java/xyz/playedu/api/domain/CourseAttachment.java
+++ b/src/main/java/xyz/playedu/api/domain/CourseAttachment.java
@@ -47,7 +47,7 @@ public class CourseAttachment implements Serializable {
     /** 附件名 */
     private String title;
 
-    /** 附件类型 */
+    /** 类型 */
     private String type;
 
     /** 资源id */
@@ -57,6 +57,10 @@ public class CourseAttachment implements Serializable {
     @TableField(exist = false)
     private String url;
 
+    /** 资源类型 */
+    @TableField(exist = false)
+    private String ext;
+
     /** */
     @JsonIgnore private Date createdAt;
 
@@ -85,6 +89,9 @@ public class CourseAttachment implements Serializable {
                 && (this.getTitle() == null
                         ? other.getTitle() == null
                         : this.getTitle().equals(other.getTitle()))
+                && (this.getExt() == null
+                        ? other.getExt() == null
+                        : this.getExt().equals(other.getExt()))
                 && (this.getType() == null
                         ? other.getType() == null
                         : this.getType().equals(other.getType()))
@@ -107,6 +114,7 @@ public class CourseAttachment implements Serializable {
         result = prime * result + ((getCourseId() == null) ? 0 : getCourseId().hashCode());
         result = prime * result + ((getSort() == null) ? 0 : getSort().hashCode());
         result = prime * result + ((getTitle() == null) ? 0 : getTitle().hashCode());
+        result = prime * result + ((getExt() == null) ? 0 : getExt().hashCode());
         result = prime * result + ((getType() == null) ? 0 : getType().hashCode());
         result = prime * result + ((getRid() == null) ? 0 : getRid().hashCode());
         result = prime * result + ((getUrl() == null) ? 0 : getUrl().hashCode());
@@ -124,6 +132,7 @@ public class CourseAttachment implements Serializable {
         sb.append(", courseId=").append(courseId);
         sb.append(", sort=").append(sort);
         sb.append(", title=").append(title);
+        sb.append(", ext=").append(ext);
         sb.append(", type=").append(type);
         sb.append(", rid=").append(rid);
         sb.append(", url=").append(url);