1. If the battery of your Xiaomi mobile phone is detachable, check whether the battery interface is in poor contact and whether to restart it. Many of them are for this reason.
2. Take off the SIM card and try it. There are countless restart problems after a friend Xiaomi's mobile phone is inserted into the SIM card. After the SIM card is removed, the fault disappears. If there is, you have to go to after-sales maintenance;
3. Some millet models will restart automatically by pressing the power button 10 second by default. You can check whether the power button is faulty. This situation can only be repaired;
4. If it is not a hardware problem, you can try to update the system, or find a professional to brush the machine, but brushing the machine is risky, so be careful.