The thermal deformation of machine tool spindle influences the performance of the manufacturing systems for precision products. According to previous studies, major factors that will affect the stiffness of the spindle include spindle diameter, elasticity of the material, bearing stiffness and bearing span. It is difficult to change spindle diameter or elasticity of the material. but change of bearing position is easy in the given range compared to other factors. In this paper, we will find a solution to minimize thermal deformation through Change the span of the bearing.