The invention discloses a control method for a variable frequency air conditioner adopting a duplex cylinder compressor. When the air conditioner is opened by a user, an infrared sensor conducts real-time detection; when a controller judges that the user leaves the room and the leave time arrives a preset time I, the temperature set by the user is adjusted to a temperature close to the outdoor environment temperature; when the controller judges that the user leaves the room and the leave time arrives a preset time II, the air conditioner stops. According to the method provided by the invention, the purpose of decreasing air conditioner energy consumption is realized.