CNC milling machine also known as cnc(computer numerical control) milling machine.A milling machine controlled by a digital signal with an electronic meter.[1] NC milling machine is a kind of automatic machining equipment developed on the basis of general milling machine. The processing technology is basically the same and the structure is similar.Numerical control milling machine can be divided into two categories: without tool library and with knife library.The NC milling machine with tool storehouse is also called the machining center.