In order to obtain 3D solid model of an Oerlikon system’s prolate epicycloidal bevel gear by full generating processing, the solid modeling method for the gear was studied in Pro/E. First, Drawing benchmark circles (base on the circle and reference circle as well as tip circle and root circle)and involute tooth profile of virtual equivalent gears of both large end and small end of the real gear, and then an intercepted segment of prolate epicycloid which has the same trend to the tooth and is controlled by prolate epicycloidal equations is projected to the surface of the gear’s root cone for the sake of getting tooth curve along axial direction. In the end, along the tooth curve and on the root cone conducting a variable cross section solid scanning to tooth shaped cross section, a complete gear tooth will be gained and at last model establishing will be finished. This method provided digital basis for optimization design, reverse design and rapid prototyping of this kind of gear, and so its design efficiency is improved.