Gear modeling method and gear modeling device

The invention provides a gear modeling method and a gear modeling device, wherein the gear modeling method comprises the following steps of: generating models of a rack cutter and a gear blank; performing cutting motion of gear processing through simulating the rack cutter in relative to the gear blank by using the models of the rack cutter and the gear blank so as to obtain the position of each point on preset gear shape of the rack cutter at each analogue cutting moment; determining the position of a cutting point of cutting at each analogue cutting moment; determining the position of a cutpoint on the corresponding gear blank at each analogue cutting moment so as to obtain a gear shape outline of the gear; and generating the model of the gear according to the gear-shaped outline. The modeling method provided by the invention is capable of truly reflecting the shape of the practically processed tooth root transition curve based on processing and enveloping processes of the rack cutter and capable of realizing turbine modeling; and the modeling precision is high.