The is based on PC platform CAD/CAM software that Mastercam is development of American CNC company, it had convenient and intuitionistic geometrical modelling Mastercam to provide the perfect environment that place of appearance of design spare parts wants, the modelling function that its stabilize formidably can design part of complex curve, curved surface. Mastercam has driving curved surface rough machining and function of agile curved surface finish machining. Mastercam offerred a variety of advanced rough machining technologies, in order to improve the efficiency that the spare parts machines and quality. Mastercam still has function of rich curved surface finish machining, can choose best method from which, machine the most complex part. The much axis of Mastercam machines a function, the treatment that is a spare parts provided more flexibility. Mastercam of reliable function of desired result of cutting tool method but the whole process that imitate spare parts machines, in imitate not only can show cutting tool and clamping apparatus, still can check cutting tool and clamping apparatus and by circumstance of the interference of treatment spare parts, collision. The postposition transaction file that Mastercam offers 400 kinds of above is planted with applying to each the numerical control system of the type, what my factory uses is FANUC system, the machine tool is milling machine of four-axle linkage horizontal. According to the actual structure of the machine tool, we wove special postposition transaction file, postposition of classics of file of NCI of method of cutting tool of treatment of stringy chamfer curved surface creates machine program after processing. Use Mastercam realizes DNC treatment, DNC (direct numerical control) it is to point to control machine tool of much stage numerical control directly with a computer, its technology is one of crucial technologies that implement CAD/CAM. Because this work is greater, the data of processing is much, creates program is long, the magnetism bubble memory of numerical control machine tool already cannot satisfy the requirement that the program measures, must use DNC to machine means so, use RS-232 serial interface, rise the computer and join of numerical control machine tool. The Communic function that uses Mastercam has news report, and the memory that need not consider a machine tool is not worth a problem, via many practice, weave with Mastercam software the machine program of complex part is very convenient, and can undertake to machining a process real time is emulated, real report machines the actual condition in the process, be worthy of be one outstanding CAD/CAM software. CNC MillingCNC Machining