A method for cleaning an air conditioner indoor unit and outdoor unit includes controlling a heat exchanger to enter a self-cleaning mode, adjusting an operating frequency of an air conditioner, an opening of a throttling device, and a corresponding fan speed of the heat exchanger, and maintaining an evaporating temperature of the heat exchanger within a present range to enable a frost process on a surface of the heat exchanger. When a differential pressure of the air conditioner meets a preset condition, a four-way valve changes a direction, switching defrosting to indoor and outdoor heat exchangers. When the differential pressure does not meet the preset condition, the air conditioner is adjusted to meet the preset condition and the four-way valve direction is changed to perform a defrosting switching to the indoor and outdoor heat exchangers.