If you have more than 1 user in your deepin, try this:
1. Super + L to lock your screen.
2. Click on the users icon showed on the lock screen. ( your users will be showed )
3. Ctrl + Alt + F1 to open the fullscreen terminal.
4. Ctrl + Alt + F7 to leave the fullscreen mode.

Now you're back logged in your user without having to put your password.

It only happens when you have more than 1 User.