The invention provides an air conditioner EMC (
electro magnetic compatibility) optimization circuit, an air conditioner controller and an air conditioner. The air conditioner EMC optimization circuit comprises a ground wire, a
rectifier bridge, a low-impedance path, a PFC (
power factor correction) circuit and an
inverter circuit, wherein the PFC circuit and the
inverter circuit are sequentially connected with the output end of the
rectifier bridge. The PFC circuit and the
inverter circuit are connected with the ground wire through a distributed
capacitor, one end of the low-impedance path is connected with the output end of the
rectifier bridge, and the other end of the low-impedance path is connected with the ground wire. According to the air conditioner EMC optimization circuit, the air conditioner controller and the air conditioner, on the premise that the basic architecture of an air conditioner variable-frequency controller circuit is not changed, the low-impedance path is additionally arranged in the controller circuit, the high-frequency common-mode interference
noise transmitted from the PFC circuit and the inverter circuit is transmitted to the PFC circuit and the inverter circuit again through the output end of the low-impedance path and the output end of the rectifier bridge, the high-frequency common-mode interference
noise can flow back to an interference source and cannot be transmitted to a power line from the ground wire, and therefore the common-mode
noise interference transmitted by the controller circuit is reduced, the common-mode current flowing to an LISN (
line impedance stabilization network) is reduced, and the EMC test margin is increased.