Abstract: The grooved wheel is a typical representative of 4-axis machining process; when the grooved wheel parts are milling, whose machining process directly affects the residual amount of the piece and the over-cutting quantity, which is an urgent process of studying and improving in machining and manufacturing. In this paper, UG and VERICUT are used to simulate machining of the grooved wheels, and the machining parameters of the wheel pieces are set reasonably; the machining procedure of the parts is verified through simulation, and the machining allowances and overcutting phenomenon of the parts are then analyzed. The findings show that VERICUT simulation can intuitively simulate the whole process of CNC machining, shortening the machining time of specimens and samples, and the control residual margin in the simulation is ±0.1mm, while the overcutting and residual is ±0.1mm, which effectively reduces the amount of the process of polishing after milling, thus improving the safety of the first machining, as well as increasing the economic benefits of the small and medium-sized enterprises.