Special shaped-screw is widely used in some industries, and the machining process is different trom most normal parts. A new method of numerical control(NC) programming to machine screw is proposed, in which the screw face is cut by cutter moving through screw curve track. The method can be used in machining screw with line-shaped groove and curve-shaped groove. Screw process and machining tools are introduced. Computing coordi-nates of cutter location points, NC programming, cutting method, Computing tool step, and Computing stepover length are researched. The application results verify the validity of the present techniques.