The proton therapy facility was designed in China for the first time.Elastic deformation of driving rollers at contact area will arise from hugeness and ponderousness of the facility.For the deformation

the shape of the contact area changes from theoretical line to the surface and the true transmission ratio cannot agree with the theoretical value

which results in the reduction of transmission accuracy.The approximate deformation tendency of driving rollers was obtained according to the elastic slide theory and hertz contact theory.A finite element analysis(FEA) model for driving rollers of the proton therapy facility was performed by simulating the boundary conditions and the force conditions of driving rollers

using ANSYS WORKBENCH software.Effective basis was provided for the design and adjustment of the proton therapy facility based on FEA and study of the mechanical behavior of rollers.