Using the software ABAQUS, a three dimensional thermo mechanically coupled FEM model of HN900×300 rough rolling process was established, in which, the roller was made as deformable body to research its strength situation and deformation regularity, and the influence to the workpiece from the roller' s elastic deformation was taken into consideration too. Based on the simulation results, the principal stress and shear stress of roller as well as its compression deformation and bending deflection were discussed emphatically. Compared the analytical rolling force results to the practical rolling process, this method could provide some valuable references to the rolling practice.