The radial electromagnetic force of the pulse vibration acts as an excitation source on the stator tooth surface of a 12/8-pole single-winding bearingless switched reluctance motor wider with rotor tooth （BSRMWR） and transmits it to the stator yoke and the stator yoke， which causes a large vibration and noise and hinders its popularization and application. In view of this problem， this paper optimizes and improves the motor housing from the perspective of the body structure. Using the three-dimensional multiphysics finite element model， the electromagnetic-structure-vibration-sound field coupling model of BSRMWR is established. The radial electromagnetic force is obtained by transient analysis of the BSRMWR electromagnetic field. The modal strain energy method is applied to the shell of BSRMWR， and the motor shell structure has a large strain energy， which shows that the motor shell structure is weak. Based on this， the casing structure of the motor is optimized by the method of morphology optimization. The results show that the vibration and noise of the BSRMWR with the chassis structure optimized by the topography are significantly improved.