<p>In order to find out the main electromagnetic vibration source of the integer-slot multi-pole PMSM for EVs, and to provide the theoretical basis for suppressing the vibration of the motor from the source, the harmonic components of the electromagnetic force are analyzed in this paper. The relationships between the radial and tangential forces and the modulation effect of the stator teeth on the higher-order forces are studied. It is pointed out that part of tangential and high-order force harmonics will also have a greater impact on the motor electromagnetic vibration. A 48-slot 8-pole interior permanent magnet synchronous motor (IPMSM) is taken as a prototype and the electromagnetic vibration responses under a wide speed range are calculated by multi-physics finite element simulation. Combined with the theoretical analysis, it is pointed out that the main vibration sources of the prototype are the 0th- and 48th-order 12<i>f</i> radial and tangential electromagnetic force harmonics produced by the interaction between the fundamental harmonic of the air-gap flux density and the first order tooth harmonic. Finally, by comparing the simulation results with the experiment, it is found that the average error is less than 10%, which verifies the accuracy of the simulation results.</p>