Ｔhe order analysis method for studying the rotary machinery vibration signal and transfer path analysis(TPA) method are used to diagnose the excitation source and the greatest contribution of transfer path, it leads to the booming noise in a passenger car. The modal test is used to measure and analyｚe the first bending nature frequency. It is found that the booming noise is caused by the forced dynamic response of transmission shaft in the resonant state. Based on the dynamic vibration absorber method, the mechanical parameters of the absorber are designed. A modification of the transmission shaft is provided to reduce the interior noise of the car and control the booming noise. The road testing proves that the visibility is improved.