CNC machining route refers to the determination of numerical control lathe feed processing route tool from the knife point movement began fixed origin (or machine), until the return to that point and end the route processing program, including cutting paths and cutting tool cut, cut out of the empty travel path. Finishing the feed line are basically along the contour order, therefore, to determine the feed line focus is to determine the rough machining and empty trip feed line. In the numerical control lathe processing, processing route to determine the general should follow the principle of the following aspects. 1) should be able to guarantee the machining precision and surface roughness. (2) reduce processing route, the shortest travel time, improve the machining efficiency. (3) try to simplify the numerical calculation workload, simplify the processing procedure. (4) for the repeated use of certain procedures, should use a subroutine.