A power controller, including a supercapacitor, a motor, a transistor switch, an electric signal processor, an output resistor, a sampling resistor, a filter capacitor, a voltage-stabilizing circuit, a flyback diode, and a switch. The supercapacitor is connected in parallel to the motor, the transistor switch, and the sampling resistor to form a main working circuit. The signal output end of the electric signal processor is connected to a trigger electrode of the transistor switch via the output resistor. The sampling end of the electric signal processor is connected to the sampling resistor. The motor is connected in parallel to the flyback diode. The sampling resistor is connected in parallel to the filter capacitor. The Vcc end of the electric signal processor is connected to the supercapacitor via the voltage-stabilizing circuit. The state control ends of the electric signal processor are connected to the GND or Vcc of the electric signal processor via the switch.