Although UPS is known as the "God of Computer Protection", no protection is foolproof. Even UPS with good quality and complete protection circuits is difficult to withstand extreme harsh power supply environments such as lightning strikes. However, there are many low-end household UPS without reliable mains voltage stabilization and protection circuit, so it is not surprising that they fail to play a protective role under such bad circumstances. As for low-quality low-quality UPS, let alone the low-quality UPS. Therefore, in the harsh environment of mains power supply, we should purchase famous brand UPS with mains voltage stabilization function as much as possible.