Electronic Devices TIAN Wang-lan, LI Jia-sheng 5 1 2016 http://www.dline.info/ed/fulltext/v5n1/edv5n1_1.pdf The switch on of AC-DC Buck converter brings harmonic waves to the grid, and causes the decline of power factor, affects the grid power quality. This paper comparing with the current harmonic suppression methods, considering to employs PID control, as the manual regulation of parameters, it is hard to achieve good controlling effect.It proposes an inverter harmonic suppression method based on genetic algorithm PID control. It gives the AC-DC Buck converter circuit structure and controlling model, analyzes the operating principle and conducts simulation verification. The simulated results show that this method can suppress harmonic effectively and improve the power factor, which has certain utility value in practical application.