The emergence of CNC machine tools is great progress in the performance of the industry, it can better solve the complex, precision, small-batch, changeable parts processing problems, is a flexible, high efficiency of automatic machine tools. Programming personnel in the use of NUMERICAL control machine tool processing, the first to carry out process analysis. According to the material of the workpiece being processed, contour shape, processing accuracy, and so on, choose the appropriate machine tool, develop the processing scheme, determine the processing order of the parts, the tools used in each process, fixture, and cutting dosage. Here is how to develop processing steps for CNC machine tools: