The invention discloses a method for controlling an air conditioner, and belongs to the technical field of air conditioners. The method for controlling the air conditioner comprises the steps that under a refrigerating mode of the air conditioner, an indoor temperature t and an indoor humidity RH are collected; whether the condition is met or not is judged according to the indoor temperature t andthe indoor humidity RH, if yes, the rotation speed R of an indoor draught fan is controlled according to an indoor coil pipe temperature Tpn and the indoor humidity RH, and the working efficiency F of a compressor is adjusted according to the rotation speed R of the indoor draught fan. The invention further discloses a device for controlling the air conditioner and the air conditioner.