diff --git a/backend/apps/projects/serializers.py b/backend/apps/projects/serializers.py
index 6fd846c..dcfd905 100644
--- a/backend/apps/projects/serializers.py
+++ b/backend/apps/projects/serializers.py
@@ -9,7 +9,7 @@ class ProjectSerializer(serializers.ModelSerializer):
         fields = [
             'id', 'name', 'template_id',
             'card_width', 'card_height',
-            'design', 'card_overrides', 'number_layout', 'face_orientations',
+            'design', 'back_design', 'card_overrides', 'number_layout', 'face_orientations',
             'export_resolution', 'export_include_back',
             'created_at', 'updated_at',
         ]
@@ -47,7 +47,7 @@ class ProjectDetailSerializer(serializers.ModelSerializer):
         fields = [
             'id', 'name', 'template_id',
             'card_width', 'card_height',
-            'design', 'card_overrides', 'number_layout', 'face_orientations',
+            'design', 'back_design', 'card_overrides', 'number_layout', 'face_orientations',
             'export_resolution', 'export_include_back',
             'assets', 'layers',
             'created_at', 'updated_at',
diff --git a/backend/apps/projects/views.py b/backend/apps/projects/views.py
index 006e811..a337f2d 100644
--- a/backend/apps/projects/views.py
+++ b/backend/apps/projects/views.py
@@ -26,6 +26,8 @@ def project_list(request):
             data['card_overrides'] = Project._meta.get_field('card_overrides').default()
         if 'number_layout' not in data:
             data['number_layout'] = Project._meta.get_field('number_layout').default()
+        if 'back_design' not in data:
+            data['back_design'] = Project._meta.get_field('back_design').default()
         # 抽出 template_id（不写进 Project 字段）
         template_id = data.pop('template_id', None)
         serializer = ProjectSerializer(data=data)
@@ -82,13 +84,14 @@ def project_save_design(request, pk):
     except Project.DoesNotExist:
         return Response({'error': 'Project not found'}, status=status.HTTP_404_NOT_FOUND)
 
-    for field in ('design', 'card_overrides', 'number_layout', 'face_orientations'):
+    for field in ('design', 'back_design', 'card_overrides', 'number_layout', 'face_orientations'):
         if field in request.data:
             setattr(project, field, request.data[field])
     project.save()
     return Response({
         'ok': True,
         'design': project.design,
+        'back_design': project.back_design,
         'card_overrides': project.card_overrides,
         'number_layout': project.number_layout,
         'face_orientations': project.face_orientations,