For non-zero-modification transmission spiral bevel gear, its machining parameters can be designed with local synthesis. This new design method can correct the shortage of non-zero-positive transmission, because it lets contact ratio decline with mesh angle increasing. Two different designs about stress analysis were compared by using an example. With the same load, the new design made pinion root stress reduced obviously then traditional design, the maximal root stretched stress reduced 27.6%, the maximal root compressed stress reduced 23.5%, the maximal tooth contact stress reduced 6.5%, and gear root stress also reduced a little. New tooth profile and machining parameters design prolonged the gear set life and higher its reliability.