Provided are a method and device for controlling an air conditioner. The method comprises: acquiring a current indoor temperature in an air conditioner control region and an initial user-set temperature of the air conditioner; and adjusting the initial user-set temperature when an indoor temperature is detected to meet a preset condition, energy consumption corresponding to the adjusted set temperature being lower than energy consumption corresponding to the initial user-set temperature. The method reduces power consumption of the air conditioner while ensuring that the temperature of the air conditioner is basically in line with expectations.