我认为问题出在您的 EmailAuthBackend 中。如果您在后端添加一些打印/日志记录，则会发现登录表单使用用户名和密码调用身份验证方法。这意味着电子邮件为无，因此 user = User.objects.get（电子邮件=电子邮件）查找失败。

I think the problem is in your EmailAuthBackend. If you add some printing/logging to the backend, you'll find that the login form calls the authenticate method with username and password. This means that email is None, and therefore the user = User.objects.get(email = email) lookup fails.

在您的情况下，常规 ModelBackend 可以正常工作，因为您有 USERNAME_FIELD ='email'。如果您从设置中删除 AUTHENTICATION_BACKENDS ，则该登录应该有效。然后，您可以删除您的 EmailAuthBackend 。

In your case, the regular ModelBackend will work fine for you, because you have USERNAME_FIELD = 'email'. If you remove AUTHENTICATION_BACKENDS from your settings then the login should work. You can then remove your EmailAuthBackend.

如果您想使用其手机号和密码（和 cell_number 不是 USERNAME_FIELD ，那么您将需要自定义身份验证后端。还需要一个名为 authenticate（cell_number = cell_number，password = password）的自定义身份验证表单，另一个支持自定义身份验证的示例是 RemoteUserBackend ，它根据服务器设置的环境变量登录用户。

If you wanted to log in users with their cell number and password (and cell_number was not the USERNAME_FIELD, then you would need a custom authentication backend. You would also need a custom authentication form that called authenticate(cell_number=cell_number, password=password). Another example of a custom authentication backed is RemoteUserBackend, which logs in the user based on an environment variable set by the server.