It may be caused by the following reasons:
1. The watch is in a low power state and is not charged in time. After a period of use, the watch will automatically shut down.
2. When the watch reaches the set automatic shutdown time point, it will automatically shut down.
3. The watch has the function of overtemperature protection. If the working temperature of the watch is higher than 45 ° C, the watch will automatically shut down. Perform the following operations to rectify the fault. If the fault persists, go to Huawei customer service center with the purchase certificate.