An air conditioner, a method and a device for controlling a compressor in the same are disclosed in the present disclosure. The method includes: during a shutdown process of the air conditioner, controlling a drive circuit of the compressor to short three phase windings of the compressor if receiving a stop signal for stopping the compressor; and controlling a rotor of the compressor to stop according to a brake torque generated by shorting the three phase windings, to stop the compressor. The method shorts the three phase windings by controlling the drive circuit, thus to generate the brake torque to control the rotor to stop faster. As a result, the method enables the compressor to stop and to stay still rapidly, thereby facilitating to reduce a piping stress in the air conditioner and to prolong a working life of a pipe in the air conditioner.