Abstract: By the study to the principle of kinematics, a special property for the curve line on curved surface is found, that is the curve line is with a characteristic traverse guage on it. So the characteristic machining method to imatate the movement of characteristic traverse guage along the curve line is presented. As an example for machining the helicoid with special shape by the characteristic machining method, the conical miller with equal helix angle ground by disk typed wheel is shown.

Key words: Curved surface, Helicoid, Kinematics, Machining