Abstract: To reduce contact deformation between the supporting device and the contact area of the rotating gantry rollers, this paper mainly uses the workbench to perform finite element analysis on the contact deformation from two aspects of the layout of the ribs of the rotating gantry roller and the contact width with the supporting roller of the supporting device. The results show that for the proton therapy equipment corresponding to this article, the contact deformation is relatively small and the structure is more reasonable when the ribs are close to the symmetrical position and the contact width between the rotating gantry roller and the supporting roller of the supporting device is 200 mm. This article provides theoretical basis for the design of the proton radiotherapy equipment supporting device.