Abstract: The electromagnetic vibration of the three-phase asynchronous motor under no load condition is studied in the paper. A time-stepping finite element model of the three-phase asynchronous motor is built to calculate the transient electromagnetic field, and Maxwell stress tensor method is adopted to capture the radial electromagnetic force under steady state no load condition. To detect the main harmonics contained in radial electromagnetic force, the comparison between the spectral analysis and analytic calculation is done. A 3D structural finite element model of the asynchronous motor is formed with Ansys software. The radial electromagnetic force is exerted on the surface of stator and the electromagnetic vibration is computed. Finally, simulation and experiment results are compared to verify the veracity of simulation analysis. Experimental results show that the method proposed in this paper can be applied to calculate the electromagnetic vibration at motor design stage.