Transformation principle and method for machine settings from cradle-type hypoid generator to Free-From CNC one was studied. Appling coordinate transformation, the mathematical model of tilt method process for hypoid gears was proposed, which can be used for simulation face milling and face hobbing process. By auxiliary coordinate systems, the relative position and motion between the head-cutter and the workpiece during the two generation process was established, and transformed to Free-Form coordinate system, to obtain and to expand the expression of 6 CNC axes. A numerical example was also employed to verify the proposed method, and the TCA results proved that transformation is feasible.