diff --git a/apps/assets/models/authbook.py b/apps/assets/models/authbook.py
index 895268b2a..87e96c3fe 100644
--- a/apps/assets/models/authbook.py
+++ b/apps/assets/models/authbook.py
@@ -3,7 +3,6 @@
 
 from django.db import models, transaction
 from django.db.models import Max
-from django.core.cache import cache
 from django.utils.translation import ugettext_lazy as _
 
 from orgs.mixins.models import OrgManager