The design, modeling and simulation are one of the key technologies of CAD/CAM software system. The mathematical model of the CAD/CAM system for machining spatial surface was given firstly. After the design idea of the CAD/CAM system was describe in detail, the workflow of the CAD/CAM software system was illustrated, and then data exchange mechanism was determined and detailed steps were given simultaneously. Under MFC framework, the CAD/CAM software system was finished using OpenGL, and the configuration and machining process simulation were carried out. All these works provide an effective approach to raising the productivity and precision of machining spatial curve surface part by WEDM-HS.