diff --git a/apps/counter/api/serializers.py b/apps/counter/api/serializers.py
index 7167df4..aa332b5 100644
--- a/apps/counter/api/serializers.py
+++ b/apps/counter/api/serializers.py
@@ -1,7 +1,5 @@
-import pytz
 from django.db.models import Q
-from datetime import datetime, time
-from django.db.models import Sum
+from django.core.cache import cache
 from rest_framework import serializers
 from counter.models import DeviceCount, DeviceInfo
 from mosquito.models import DeviceInfo as CelexDeviceInfo
@@ -42,10 +40,16 @@ class DeviceCountSerializer(serializers.ModelSerializer):
         return obj.data_time.strftime('%Y-%m-%d %H:%M:%S')
 
     def get_device_name(self, obj):
-        qs = CelexDeviceInfo.objects.filter(device_id=obj.device_id)
+        device_id = obj.device_id
+        cache_content = cache.get(device_id)
+        if cache_content:
+            return cache_content
+        qs = CelexDeviceInfo.objects.filter(device_id=device_id)
         if qs.count() > 0:
             device = qs[0]
-            return device.device_name
+            device_name = device.device_name
+            cache.set(device_id, device_name, 60 * 60 * 24)
+            return device_name
         return None
 
 
diff --git a/apps/counter/mixins/role.py b/apps/counter/mixins/role.py
index 81b6c3a..13d0ce7 100644
--- a/apps/counter/mixins/role.py
+++ b/apps/counter/mixins/role.py
@@ -13,7 +13,7 @@ class RoleMixin(object):
 class DeviceListMixin(object):
     @staticmethod
     def get_device_list():
-        if cache.has_key('device_list'):
+        if cache.get('device_list'):
             device_list = cache.get('device_list')
         else:
             device_list = DeviceInfo.objects.get_queryset().order_by('-online')