In order to explore the generation mechanism of friction noise of air-conditioning rotor compressor,a method to predict the frictional noise of the air-conditioning compressor by using finite element method was proposed.The modal analysis of the finite element model of air-conditioning rotor compressor friction system was performed by complex eigenvalue analysis method,the natural frequency of the friction system and the change characteristics of the corresponding mode shape were obtained,and the frequency that may cause frictional noise was inferred.The calculated results of the finite element model are in good agreement with the measured data,which verifies the effectiveness of the prediction method.The results show that the introduction of friction in the crankshaft and flange friction system may cause modal coupling of the system,resulting in unstable vibration and noise.The changes in friction coefficient and flange elastic modulus have a significant impact on the formation of frictional noise.Increasing the critical friction coefficient of the friction system can improve the stability of the friction system to a certain extent.When the elastic modulus of the flange is higher,the friction system is more likely to produce friction noise.