The invention discloses a compressor control method of a variable frequency air conditioner of a railway vehicle. During startup and shutdown control, the temperature difference is used as a judgmentcondition, and the total running time or the continuous running time is added as a judgment condition, so that the compressor can be started immediately, capacity output can be performed quickly, thetarget temperature in the passenger room can be reached quickly, and matching of startup and shutdown of the compressor and actual requirements in the passenger room is realized; when the operation frequency is controlled, the duration time is also increased as a judgment condition; the operation frequency of the compressor is continuously adjusted according to the change of the heat load in the passenger room; the output capacity of the air conditioner is optimal; the actual temperature in the passenger room is always stabilized within the range of +/-1 DEG C of the indoor target temperature,so that the phenomenon of passenger room temperature fluctuation caused by frequent opening and closing of the compressor can be reduced, the passenger room is more comfortable and energy-saving, meanwhile, the operation frequency of the compressor is matched with the actual requirement in the passenger room, and the influence on the service life of the compressor is reduced.