Abstract: In development of open numerical control systems,there are numerous hardware and software in the market of the home and abroad. This paper utilizes the AHP method in the architecture mathematical modeling, the open CNC (Computer Numerical Control) system is successfully selected to meet ideal demand. This system is a PMAC-NC (Programmable Multi-axis Controller Numerical Control) system, in which numerical control machine tools is controlled by PMAC multi-axis motion controller. The system can meet the require of engineering and instruction.