A power tool, comprising: a motor; a power supply interface configured to be connected to a power supply; a controller configured to control the operation of the motor, wherein the controller comprises a first controller and a second controller; an auxiliary power supply circuit configured to power on the controller; a signal switch triggerable by a user to switch a power on/off state of the power tool; a signal detection circuit connected between the signal switch and the controller and configured to output a corresponding detection signal according to a connection state of the signal switch, wherein the detection signal comprises a power-on signal and a power-off signal; a power-on control switch connected between the auxiliary power supply circuit and the second controller and configured to control a power-on state of the second controller; and a driver circuit connected between the second controller and the motor, comprising several semiconductor switch elements, and configured to switch an energized state of the motor; wherein the first controller is electrically connected to at least the power-on control switch and configured to control an on/off state of the power-on control switch, wherein the second controller is connected to at least the signal detection circuit, the power-on control switch, and the driver circuit and configured to control on/off states of the switch elements in the driver circuit; wherein in a case where the signal detection circuit outputs the power-off signal, the first controller is configured to control the power-on control switch to be turned off so that the second controller is de-energized and the motor stops rotating; wherein in a case where the signal detection circuit outputs the power-off signal and the power-on control switch still remains on, the second controller is configured to control the switch elements in the driver circuit to be turned off so that the motor stops rotating; characterized in that said power tool is configured to keep said driver circuit connected to said power supply interface when said power tool is switched to its power-off state. a motor; a power supply interface configured to be connected to a power supply; a controller configured to control the operation of the motor, wherein the controller comprises a first controller and a second controller; an auxiliary power supply circuit configured to power on the controller; a signal switch triggerable by a user to switch a power on/off state of the power tool; a signal detection circuit connected between the signal switch and the controller and configured to output a corresponding detection signal according to a connection state of the signal switch, wherein the detection signal comprises a power-on signal and a power-off signal; a power-on control switch connected between the auxiliary power supply circuit and the second controller and configured to control a power-on state of the second controller; and a driver circuit connected between the second controller and the motor, comprising several semiconductor switch elements, and configured to switch an energized state of the motor; wherein the first controller is electrically connected to at least the power-on control switch and configured to control an on/off state of the power-on control switch, wherein the second controller is connected to at least the signal detection circuit, the power-on control switch, and the driver circuit and configured to control on/off states of the switch elements in the driver circuit; wherein in a case where the signal detection circuit outputs the power-off signal, the first controller is configured to control the power-on control switch to be turned off so that the second controller is de-energized and the motor stops rotating; wherein in a case where the signal detection circuit outputs the power-off signal and the power-on control switch still remains on, the second controller is configured to control the switch elements in the driver circuit to be turned off so that the motor stops rotating; characterized in that said power tool is configured to keep said driver circuit connected to said power supply interface when said power tool is switched to its power-off state.