Numerical control lathe feeding route refers to the path through which the turning tool moves from the point of view of the cutter (or the fixed origin of the machine tool) until it returns to the point and ends the processing procedure, including the path of cutting and cutting, and other non-cutting free travel paths. 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.