设计了一种用于经济型数控的通用型步进电动机微步驱动系统，该系统由一片８０３１单片机作为ＣＰＵ，可以用于额定电流３Ａ以下的三相、四相、五相反应式步进电动机的微步驱动。由于其灵活的软硬件设计，系统可以方便地用于脉冲驱动、ＲＳ２３２接口、ＣＴＤ总线接口等场合。文中着重介绍了系统的软硬件设计。 A universal micro-step driving system for stepper motor of economical NC is designed. The system consists of an 8031 ​​single-chip microcomputer as CPU and can be used for three-phase, four-phase and five-phase reaction stepper motors with rated current less than 3A Micro-step drive. Because of its flexible hardware and software design, the system can be easily used for pulse drive, RS232 interface, CTD bus interface and other occasions. This article focuses on the system hardware and software design.