Combined with gear meshing mechanism and motion relationship, in the analysis of roller gear processing technology, rolling gear machining parameter model and zero-programming mathematical model were established.The NC program automatic generation technology of CNC gear-hobbing processing was studied, and the zero-programming system architecture of open CNC gear-hobbing machine was presented. The man-machine interaction, the programming algorithm and each function module design were completed, and the function test was carried on, the anticipated design request was basically achieved.