Gear transmission is an important branch and gear is used most universally in mechanisms. Considering the constitution of involute gear figure and the character of gear transmission

the accurate mathematical model of 3D geometry model and gear transmission is established. Combined with OpenGL

the 3D geometry for gear and bevel gear is built in Visual C + +

and the simulation of gear transmission is implemented based on OpenGL Double Buffer. The data of gear can also be used in numerical control machining

and the realization of simu-lation of gear transmission has a further value for parametrical design

which validates the validity of the mathematical model of gear. Thismodel can be applied in virtual prototype modeling.