Who can tell me how to remove this toolbar next to Samsung mobile phone?

The following actions are recommended: 1. Pull down the menu on the top curtain of the mobile phone-turn off the multi-window switch (enter the mobile phone settings-display-multi-window and uncheck it).

2. If it is a third party similar to the native multi-window application, you can uninstall the mobile phone management software such as mobile phone housekeeper and security guard installed in the mobile phone.

3. Back up mobile phone data (phone book, SMS, multimedia files, etc.). ) and restore factory settings (enter phone settings-reset-restore factory settings).

If the problem of restoring factory settings still exists, it is recommended to send the mobile phone to the nearest Samsung service center for testing and further processing.