A method of controlling a compressor is disclosed. The method includes: after the compressor is stopped for protection, updating the number of protective stops of the compressor occurring during a current operation of the air conditioner; and when the number of protective stops of the compressor is greater than a first preset number, lowering the frequency of the compressor so that when the compressor restarts the compressor would start and operate at the lowered frequency. Disclosed also is a device for controlling a compressor. Thus, by lowering the frequency of the compressor, the compressor would reach the high or low temperature protective value comparatively slowly, so the number of restarts of the compressor can be reduced.