For high precision contour machining,on the basis of analysis of contour errors of the system,the contour errors were reduced indirectly by diminishing the tracking errors.

Tool-path optimization for multi-contour machining was formulated as a generalized traveling salesman problem (GTSP) with changeable nodes since the cutting sequence and the starting points of contours affect the tool-path.

This paper presents the procedure all through the contour machining of characters from getting contour to generating NC code in computer-aided manufacturing software,solves the algorithm problems of sorting,direction and relation examination,radius compensation and commutation efficiently.