Dimension error and surface quality have much different between each teeth of gear, moreover directly affect the gear work. After many times grinding, grinding speed and wheel contour of grinding wheel changed. This is primary reason of different between each teeth of grinded gear. Aiming at the problem, it is advanced the method of constant speed grinding and improved the tradition grinding machine structure, optimized the function of the wheel corrector using CNC technology. Machine improved can realize constant speed grinding, moreover can rapidly and accurately trim grinding wheel used complicate surface driving parts grinding. So improve grinding quality and increase grinding efficiency.