In order to change the position control into physical motion control, and give up interpolation calculation, a physical motion model of CNC machine tool has been built. The relation between geometric parameters, motion parameters and planning parameters is studied with kinematics principle and geometric principle. The motion differential equations are worked out, It can be used to calculate transient motion parameters of coordinate axes. To control locus motion by motion parameters equals to control by motion regularity and geometric law. The numbers of trajectory point are infinity, the regularity, however, is one only. Therefore, the control method with motion regularity is a short-cut and all-sided method. It is proved by experiment and simulation that it is good way to control motion and geometric position at the same time.