Running smoothly,which is tested by hand,is one of important requirements when the ball screw is run- ning.It is a key problem that needs to pay attention to and solve urgently in the industry for a long time.So when the ball screw is loaded,the movement of ball center position is as a study and modeling before and after the ball has contact deformation in its raceway.Then the parameter designing is improved and planed as a whole with reason, and taking effective technology process.The way is successful for solving the problem.