Based on UG secondary development tools, by using parameterized design method, the solid models of cutter and gear roughcast are established,and the dynamic simulation of machining process with preshaving hobs is carried out according to the principle of gear machining.

The paper explores such problems of gears machining as antenna length calculation,shaving stock and addendum modification of preshaving hob,hoping to provide methods,which have been proved theoretically correct,of designing this kind of gear tools.

Based on the principle and method of software engineering, the CAD system of preshaving hob is developed by using the techniques of OOP, ODBC and ARX.