Air-conditioner and control method and device for compressor in air-conditioner

The invention discloses a control method and device for a compressor in an air-conditioner and the air-conditioner. The method includes the following steps that in the running process of the compressor, if a running stop command is received, the running current and the running frequency of the compressor are obtained; if the running frequency of the compressor is larger than a preset frequency threshold value, the running frequency of the compressor is decreased according to a preset frequency decreasing rate, and the running current and/or the running frequency of the compressor are/is further judged in the frequency decreasing process of the compressor; and if it is judged that the running current of the compressor is smaller than or equal to a preset current threshold value and the state lasts a preset time, and/or the running frequency of the compressor is smaller than or equal to a preset frequency threshold value and the state lasts a preset time, the compressor is controlled to halt. By means of the method, the stress of compressor piping can be reduced effectively to a certain degree when the compressor halts, and therefore the service life of the compressor piping is prolonged.