论述了开放式数控系统的基本原理以及兼容性、互换性、可移植性和扩展性等特点。介绍了以步进电机为饲服电机的CJK6 132A车床闭环数控系统的基本原理———改进的时间分割法 ,改进的时间分割法使以步进电机为驱动电机的闭环数控系统易于实现。对开放式数控系统的实现做了研究 :通过制定标准和协议 ,实现系统的开放性 ;对开放式数控系统进行层次模块化设计 :物理层、软件层设计。介绍了CJK6 132A车床闭环数控系统的特点及开放性。本系统具有良好的兼容性和扩展性 ,成本低。 Discusses the basic principles of open CNC system and compatibility, interchangeability, portability and scalability characteristics. The basic principle of CJK6 132A lathe closed-loop CNC system with stepping motor as feeding motor is introduced. The improved time-division method is introduced. The improved time-division method makes the closed-loop CNC system with stepping motor as the driving motor easy to realize. Research on the realization of open CNC system: through the development of standards and protocols to achieve the openness of the system; the level of open CNC system modular design: physical layer, software layer design. The characteristics and openness of CJK6 132A lathe closed-loop CNC system are introduced. The system has good compatibility and scalability, low cost.