The invention discloses a method for reducing resonance between an air conditioning unit and a rail vehicle, belonging to the technical field of rail vehicle air conditioning, comprising the followingsteps: step A, judging whether the air conditioning unit is powered on for the first time, if so, executing step B, otherwise executing step C; step B, calculating that carrying capacity according tothe carrying capacity signal, if the carrying capacity is lower than a certain carry capacity, executing the step B1, otherwise executing the step B2; step C, if it is detected that the compressor isstopped in the running process, the restriction of forcing the compressor to run at the rotational speed R for 5 minutes after starting the compressor again is not executed, and the compressor is directly operated according to the automatic control mode. The invention has the following beneficial technical effects: the invention avoids the natural frequency of the internal parts of the vehicle through the control logic, reduces the occurrence probability of vibration, and greatly improves the riding comfort of passengers; as that invention is realize only by optimizing the software logic, thecost loss caused by a large number of measures such as replace the shock absorber, changing the hoop and the like is avoided.