A power control circuit includes an electronic switch (20) interposed between a power unit (10) and an electronic device (30), a driving circuit (40) and a mechanical switch (50). The driving circuit receives a power-on signal from the mechanical switch, and signals the electronic switch to turn on and supply power to the electronic device in accordance with the power-on signal. The electronic device controls the driving circuit to maintain the electronic switch to be on and continue the power supply to the electronic device. The electronic device further receives a power-off signal from the mechanical switch, and signals the driving circuit to turn off the electronic switch and discontinues the power supply to the electronic device.