The invention relates to the technical field of air conditioners, in particular to an air conditioner and a control method thereof. The air conditioner comprises an upper fan assembly and a lower fanassembly, and further comprises an upper air opening corresponding to the upper fan assembly, a lower air opening corresponding to the lower fan assembly, and an air-out channel connected to the upperair opening and the lower air opening. The air conditioner control method comprises the following steps of: selecting, to be specific, selecting a refrigeration mode or a heating mode; and controlling, to be specific, in the refrigeration mode, selecting an upper and lower air-out mode or an upper air-out mode, and controlling the rotating speed of a fan in the upper fan assembly to increase at the base speed, and the rotating speed of a fan in the lower fan assembly to decrease at the base speed, in the heating mode, selecting the upper and lower air-out mode, and controlling the rotating speed of the fan in the lower fan assembly to increase at the base speed. The power of the fans is used reasonably while the comfort level is improved, and the wasting of electricity is reduced.