The machine machining coordinate system of spiral bevel gear cutting machine was established by analyzing the machining mechanism of the spiral bevel gear and the relationships between the structure and motion of the traditional mechanical spiral bevel gear cutting machine. The 3-D structure model of the heavy duty spiral bevel gear cutting machine was built, using the cutter spindle feed method instead of the traditional workpiece box feed method or the machine cradle feed method so as to increases the machine’s manufacture efficiency and machining precision, according to the machining characteristic of heavy duty spiral bevel gear. And the numerical control machining model of the heavy duty spiral bevel gear cutting machine was also proposed, by analyzing the shift principle from the traditional mechanical spiral bevel gear cutting machine’s adjustment parameter to the heavy duty numerical controls spiral bevel gear cutting machine. Finally, the instantaneous position of the heavy duty numerical control spiral bevel gear cutting machine’s kinematic axis was obtained through the example computation. The machining machine model of the heavy duty spiral bevel gear machine was built, and the simulation machining was also carried out. The functional verification requirement of spiral bevel gear machine can be satisfied by the simulation results.