diff --git a/server/apps/system/migrations/0018_auto_20210430_1156.py b/server/apps/system/migrations/0018_auto_20210430_1156.py
new file mode 100644
index 0000000..218b434
--- /dev/null
+++ b/server/apps/system/migrations/0018_auto_20210430_1156.py
@@ -0,0 +1,19 @@
+# Generated by Django 3.0.5 on 2021-04-30 03:56
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('system', '0017_userthird'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='userthird',
+            name='openid',
+            field=models.CharField(default='xx', max_length=200, unique=True, verbose_name='第三方账号'),
+            preserve_default=False,
+        ),
+    ]
diff --git a/server/apps/system/models.py b/server/apps/system/models.py
index 0afae87..5713fe8 100644
--- a/server/apps/system/models.py
+++ b/server/apps/system/models.py
@@ -229,4 +229,4 @@ class UserThird(models.Model):
 
     user = models.ForeignKey(User, on_delete=models.CASCADE, verbose_name='关联账户', related_name='third_user')
     type = models.CharField('类型', max_length=50, choices=type_choices, default='wx_mp')
-    openid = models.CharField('第三方账号', null=True, blank=True, max_length=200)
+    openid = models.CharField('第三方账号', max_length=200, unique=True)
diff --git a/server/apps/system/views.py b/server/apps/system/views.py
index ac8277f..b3a5bba 100644
--- a/server/apps/system/views.py
+++ b/server/apps/system/views.py
@@ -343,7 +343,12 @@ class UserViewSet(PageOrNot, ModelViewSet):
                         code+'&grant_type=authorization_code').content.decode('utf-8')
         info = json.loads(info)
         openid = info['openid']
-        UserThird.objects.get_or_create(openid=openid, type='wx_mp', user=request.user, defaults={'openid':openid, 'user':request.user, 'type':'wx_mp'})
+        if UserThird.objects.filter(openid=openid).exists():
+            instance = UserThird.objects.get(openid=openid)
+            instance.openid = openid
+            instance.save()
+        else:
+            UserThird.objects.get_or_create(openid=openid, type='wx_mp', user=request.user, defaults={'openid':openid, 'user':request.user, 'type':'wx_mp'})
         return Response({'wxmp_openid':openid},status=status.HTTP_200_OK)