Abstract: To attain the dominant vibration and noise sources for the design of low noise IPMSM of EVs and provide the relevant theoretical support, in this paper, the multi-physics vibration and noise analysis model of PMSM was established, and the new analysis method of noise source was proposed. By this means the characteristic parameters（force order r, force frequency fr, force amplitude/reak r fP-） and their generation mechanism of electromagnetic force wave of PMSM were theoretically analyzed firstly. Then the IPMSM multi-physics coupling vibration FEM model is set up to calculate the vibration and noise spectrum characteristics in a wide-range speed regulation. Finally the dominant noise and vibration sources were analyzed theoretically. The results show that the dominant vibration and noise sources of prototype are 12 fspectrum component of zero-order force caused by first-order tooth harmonics. In the end, the theory and finite element simulation have been verified by experiments.