Abstract: According to the gear meshing and the differential geometry theory,the tooth surface equation of orthogonal face gear is derived and the corresponding mathematical model of orthogonal shaft is founded.Computer simulation of shaping process of orthogonal face gear based on UG/Open GRIP of UG is achieved.A foundation to parametric design of involute gear cutter is provided.Shaping process of orthogonal face gear using involute gear cutter is simulated and the parametric model of face gear is generated.The process of machining face gear is shown.The radius of pointing was calculated by the approximate formula,and measured by the tool of UG.The feasibility of the method is demonstrated by comparing the two situations.