X - Y nc workbench design is an open - loop control system, its structure is simple. The realization is convenient and can guarantee certain precision. Reducing cost is the simplest application of microcomputer control technology. It makes full use of the crisis of software and hardware functions to achieve the control of machine tools; The machining range of the machine tool is expanded and the accuracy and reliability are further improved. X-y CNC workbench design is the use of 8031 single-chip microcomputer, and 2764, 6264 memory and 8155 chip and other hardware components, in the control system hardware to write certain procedures to achieve certain processing functions. The basic idea is through the circular arc or straight line interpolation program to realize to geometric processing of parts, each for a period of processing to produce certain positive &negative pulse to drive the motor, 8155 will be at the same time the corresponding processing feed information sent to the tool post in the library in order to realize to the corresponding feeding, the relative motion of the machine and cutting tool so to achieve the cutting tool and machining of the. This control system USES software interrupt control system structure and subroutine structure is simple, the condition is clear in economical numerical control application more. The interrupt structure is designed with modular structure because it is easy to modify and expand, convenient to compile, and easy to develop in the direction of multi-processing.The design of X - Y nc worktable adopts stepping motor as driving device. Stepper motor is an electromechanical digital-to-analog converter device that converts the pulse signal into an angular displacement. The principle is that each pulse generates a certain space rotating magnetic field in the stator circuit. Because the stepper motor through the three-phase ac so the number of input pulse and time interval is different, the rotor rotation speed and rotation time length is different. Since the rotating magnetic field has the effect of force when cutting the magnetic field line of the rotor, the rotating magnetic field forces the rotor to make the corresponding rotation, so the rotor can realize the rotor drive the lead screw to make the corresponding motion. This topic is stepper motor, microcomputer, interpolation principle, assembly language integrated application.Key words: numerical control; The workbench. Structure; application