With reference to the center-pressure method used often in the forging, the quality of rolled pieces internal part can be improved during three-roll cross wedge rolling by non-uniform temperature field. For gaining optimal non-uniform temperature field which improves the quality of rolled pieces internal part as much as possible, the influence of relevant thermodynamics parameters on non-uniform temperature field was studied by FEM. Combined with water-cooled experimental, the internal temperature gradient of rolled pieces on optimal non-uniform temperature field were ascertained. The method of practical optimal non-uniform temperature field was checked by mechanical analysis and three-roll cross wedge rolling experiment, and it may apply to the practical work.