The turbo generator reducer is important equipment in the ship power system and its structure and materials is the significant assurance for the naval vitality. The Pauta Criterion method is used to determine the weak link of the reducer. And that the optimum design of anti-shock characteristics is done in material and structure aspects which focus on the weak link and danger area of the reducer gear case. The results show that the safety vibration margin of the reducer could be increased using the materials with higher yield limit and also the anti-shock capability. At the same time, the safety vibration margin of the reducer could be improved by thickening the slab of the structure, and the degree of the margin of safety improvement is different due to the difference of the slab thickness modification. The research of anti-shock characteristics optimization of the generator gear case aims to offer references for the optimum design of the navy power system.