Abstract: In order to meet the requirements of CNC painting processing of special machine tools for complex tools, this paper introduces the use of Rexroth MTX micro CNC system, through the axis coupling function of the system, transforms the transmission chain relationship of traditional mechanism and cam transmission mechanism into spline table file. According to the requirements of processing technology, the machining program is compiled to realize the relief machining of various kinds of hobbing tools. The design of special HMI user interface makes the operation more simple, flexible, intelligent and has good guidance function.