A power supply system for supplying power to a chipset of an electronic device is provided. The power supply system includes a voltage converter, converting a supply voltage of a power supply into a predetermined voltage and supplying the predetermined voltage to the chipset, and a power control circuit connected between the voltage converter and the power supply. The power control circuit further includes a switch and a switch controller. The switch has a first terminal connected to the power supply, a second terminal connected to the voltage converter and a control terminal The switch controller, connected to the control terminal of the switch and the chipset, controls the switch to couple the power supply to the voltage converter according to the turning-on of the power supply system.