Though the test of a certain domestic car which cause the car body vibration and cab noise under the idle with turning on and off air conditioning system. The result of the test is analyzed by sound pressure and vibration spectrum, which analysis spectrum-frequency characteristics, affecting factors and noise sources of noise.Finding out the main noise and vibration of interior noise caused by air conditioning and refrigeration system; the car dash panel and body wall is the main transmission route of cab vibration;the people feel uncomfortable when opening the air conditioning under idle, because beat frequency is caused by the compressor and engine. It provides a certain reference for the reduction of noise and vibration of car's air conditioning and refrigeration system.