Abstract: To enhance the structure stiffness, parametric model of small-sized integrated tri-vane support bracket of secondary mirror with a 95-mm outside diameter was built by APDL language of ANSYS, and vane section parameters of the beam and the connecting pole were optimized considering fundamental frequency as the objective function. Optimized result indicated that the angle of the beam and the connecting pole evidently influenced fundamental frequency and their juncture location was near the base seat but not just at the root at the highest fundamental frequency. Based on primitive structure, new type of support bracket of secondary mirror with 6 spiral surrounded supporting ribs was designed, and supporting ribs greatly improved total structure stiffness. After optimization design, this new structure with only a 14.7 g mass increase had excellent performance that fundamental frequency was increased by 33% and mounting interface deformation of secondary mirror was reduced by 37.5% under transverse acceleration, and thus it can be a good structure adapted to mechanics environment. Parametric optimization method may improve the efficiency of modeling and simulation with multiple design variables and also the design level. Optimized result can provide powerful support for structure design with limited weight, volume and obscuration area.