Abstract: In order to realize the finish machining of the tapered tooth spiral bevel gear with spherical involute tooth profile,a circular arc on the imaginary great circular plane is taken as the cutting edge to cut the workpiece when the base cone of the gear purely rolls on the great circular plane.The circular cutting edge revolves on its own axis.The kinematic relations to forming the tooth surface of the bevel gear can be achieved by the constant rotational speed ratios among the basic cone,the great circular plane and the cutting edge,and thereby forming the cutting speed and guaranteeing that the end of the cutting edge is kept on the tooth root without interference.The experiment device and the cutting tool for finishing spiral bevel gear with spherical involute tooth profile are designed,and the correctness,validity,and the feasibility of gear cutting method are proved by experiments.The results show that using a proper circular cutting edge can form the whole tooth surface by cutting at one time,accompanied by correct tool retract.Convex surfaces and concave sides of the bull wheel and the pinion can be machined on the same machine tool without changing the cutting tool.The gears machined by this method are interchangeable and can achieve constant speed ratio transmission.