The super precision cutting is a important field of super precision machining, and it is a broad new technic. The super slippy surface can be got after colored metal and non-metal is cut by single crystal diamond cutter. Following, it can take the place of super precision grinding, the efficiency can be increased, and the precision can be guaranteed. In recent years, the single crystal diamond cutter have been broadly used in the mechanics machining field, and hold a very important position. So studying manufacturing, grinding methods, grinding equipment of single crystal diamond cutter has arisen the attention of people.The single crystal diamond is very hard, and it is a good material of cutter. But at the same time, the grinding of diamond is a difficult work. On the course of grinding single crystal diamond cutter, the grinding efficiency should be increased and the blade quality ought to be guaranteed. Currently, the imported grinders are often used in grinding of single crystal diamond cutter, such as special cutting tool grinding machine of type Rs-12, Fc-200D, using expert diamond wheel. Those machines are expensive with high machining cost, which the middle and the small enterprise can"t afford. Pointed to this problem, this subject attempts to grind single crystal diamond cutters on a general tool grinder which are much cheaper. However, the worktable of many tool grinders have not the ability of auto-reciprocating, or even though grinders have the system of hydraulic auto-reciprocating, they can"t satisfy the machining require of single crystal diamond cutter owning to the moving characteristic of hydraulic auto-reciprocating system.To solve this problem, this thesis designed a numerical control precision worktable which can realize auto-reciprocating. Stepping motor was chosen as driven element. The system adopts method of combining hardware with software and achieves control of speed. Single-chip microcomputer of AT89S52 that is the core of system controls stepping motor. This paper introduces a method for computation of raising and reducing speeds of stepping motor, including the treatment of the speed control process by discrete method and the realization of speed control on stepping motor through C language. In the part of mechanical design, The output shaft of stepping motor connects ball screw with coupling joint, and enables worktable auto-reciprocating under the support of linear rack. Experiments proved that the movement of system was steady, and the vibration was small.