Taking a 72-slot 6-pole interior variable frequency adjustable speed permanent magnet synchronous motor (VFAS-PMSM) as an example，the numerical method and finite element simulation analysis are used to compare the influence of different rotor topologies on the electromagnetic performance of the motor from the aspects of no-load back electromotive force, harmonic content, cogging torque fluctuation and loss. In addition, the influence of radial electromagnetic force on the stress of the rotor is considered. The stress and deformation of the rotor core are simulated by numerical analysis and electromagnetic-structural statics coupling. Through the prototype test, the comparison and analysis method of the rotor topological structure of the interior VFAS-PMSM is proved to be of certain guiding significance.