Abstract: On the basis of studying the theory of helical bevel gear top chamfering, the development process of helical bevel gear top chamfering software is introduced with FAGOR CNC8070-OL numerical control system as the development object. The human-machine interface design of the software uses VB.net cross-platform development, the parameter calculation logic program is written in C++ language, the parameters required by the software are supported by ACCESS 2010, and the FGUIM development software that comes with FAGOR system is used as the connection between the third-party software and the numerical control system, and the helical bevel gear tooth top chamfer software is developed, and embedded in the FAGOR 8070-OL numerical control system to realize the functions of parameter calculation, NC numerical control code generation, database management and so on.