The invention provides an air conditioner microorganism breeding restraining and MVOCs secondary pollution control method. When a compressor of an air conditioner runs, a fan of an indoor unit is controlled by an electric controller. The method is characterized in that the method comprises the following steps that a humidity control module with a humidity sensor is additionally arranged on the indoor unit of the air conditioner, an input signal of the humidity control module includes the air supply humidity and the compressor start and stop state, and an output signal includes a switch signalof the fan of the indoor unit; the humidity sensor is used for collecting the humidity of air supplied by the air conditioner, and the humidity serves as the input signal to enter the humidity controlmodule; and when the compressor does not run, operation of the fan of the indoor unit is controlled according to the humidity, and start and stop of the fan are controlled according to a preset humidity control threshold.