A power control system is electrically connected to a power function circuit including a power circuit, a coil module, a switch, and a load circuit, and includes at least one timer, a zero-current trigger unit, a status control unit, and a driver unit. The status control unit has a first status interval, a second status interval, a third status interval and a fourth status. The power control method triggers the status control unit to change the status interval when a counting time reaches one specific time interval corresponding one status interval. When a coil voltage of the coil module drops to zero from a voltage larger than a positive threshold voltage in the third status interval or the fourth status interval, the status control unit triggers to change the status interval, re-enters the first status interval, resets the timer, and triggers the driver unit to open the switch.