0.008mm。By introducing the concept of surface generation points, an instantaneous force based tool deformation calculation method and the solid modeling method of deformed tool swept volume were proposed, and the solid model of machining simulation including geometry and physical errors were generated. The machining process was shown by computer graphics dynamically and the measurement method for solid model of machining simulation was also presented. The whole system was implemented by using OpenGL and PARASOLID modeling kernel. The result of machining simulations case study and the actual machining experiments indicate that the maximum and minimum simulation errors were 0.012mm and 0.004mm respectively, and the average error was 0.008mm. 