The present invention provides a power control circuit which has a timing unit used for timing an elapsed time of current half cycle of the phase-cut AC power supply signal, outputting a current accumulated timing duration, and outputting a first control signal at a starting moment when a starting point of a half cycle of the AC power supply signal is detected; a regulating unit connected to the timing unit and comprising a temporary storage module, wherein a final reference time interval is stored in the temporary storage module, and when the current accumulated timing duration reaches the final reference time interval, the regulating unit outputs a second control signal; and a control unit connected to the detection unit and the regulating unit and used for controlling current in a load based on the first control signal and the second control signal.