This problem is caused by system reasons

1. Enter Recovery mode to flash to repair system problems.

2. Go to the miui official website, download the latest version of the system, and then import it to the root directory of the phone's memory.

3. When the phone is turned off, press and hold the volume up button and the power button, and release when the startup screen appears to enter Recovery. Enter Recoverygt; Chinese gt; Clear data gt; Clear all data. )

4. Select Simplified Chinese and confirm, use the volume button to select the power button to confirm, select to install update.zip to the system and confirm.

Select Confirm and wait for completion. Select Restart to System to enter the new system.

5. If the above operation still does not work, it is recommended to send the phone to a nearby Xiaomi after-sales service for inspection and repair.