Power control system and method thereof

A power control system and a power control method thereof applied to a computer device are provided. The computer device includes a computer system and a power system. The power system includes a plurality of voltage regulators for providing supply voltages to the components of the computer device. The power control system is coupled to the computer system and the power system and includes an overclocking frequency mode. When the computer system receives an OFF signal and enters a non-operating mode, and when the power control system is in the overclocking frequency mode, the power control system sends a SYSTEM-SHUTDOWN signal to the computer system to control the power system to enter the non-operating mode and to control the power system to keep outputting supply voltages.