A power tool includes a power connection terminal, a power system, a main control switch, and a power supply protection circuit. A power supply path is disposed between the power connection terminal and the power system. The main control switch and the power supply protection circuit are configured to control the power supply path to be completed or broken. During the use of the tool, the power tool is not restarted if the main control switch is turned on before an external power source that meets a power supply requirement is connected.