Gear preforming by cross wedge rolling is an original question for discussion, parameters such as deformation, temperature field and mechanical performance are looking forward to be researched. This paper ties the advantages of preforming by CWR and the principle of generated gear together, and the die suited for gear rolling has been designed. Based on the finite deformation theory, the coupled thermal-mechanical constitutive model of gear rolling by CWR has been established. Then FEM simulation for the forming process has been developed in MSC. SuperForm, and information gained from the simulation has been analyzed also in detail which provide references for further study of gear rolling by CWR technology.