With the wide use of earth-based laser communication system, more and more engineers like to pursue the design of lightweight structure. Nowadays, engineers often firstly depend on the project experience to design the lens hood, then make analysis based on finite element method to verify its feasibility, but it costs too much time. The paper attempts to give a new optimization design method. Surrogate model are widely used in the fields of aerodynamics parameters optimization, but barely used in design of optical structure. The paper makes an optimal design about lens hood with wide aperture based on surrogate model. First of all, the paper generates some samples by finite element method; secondly, uses the samples to get the surrogate model by surface interpolation; then finds the optimal solution by surrogate model and constraint conditions. The aperture of the lens hood in this paper is 450 mm. One end of the lens hood is attached to main structure, and the other end is free. Middle part of the lens hood is supported by rods which are made of carbon fiber. The optimization variables in this paper is the thickness of the lens hood and the location of the supports robs. The purpose of the optimization is to find the case that the weight is light and displacement of the free end is small. It will not let the miscellaneous light make a negative effect on incident or outgoing path of light. In other words, it will ensure the quality of imagining or effect of detection. The appropriate solution is found by the method proposed in this paper. © 2019 SPIE.