Abstract: To address the lightweight design requirements of large-scale phased array antenna skeletons, an optimization model was established with the objective of structural lightweighting and constraints of stiffness and strength. Aiming at the low computational efficiency of traditional optimization methods caused by frequent numerical simulation calls, this paper first proposes a hierarchical optimization design scheme based on the structural characteristics of the antenna skeleton, reducing the problem-solving dimension through layer-by-layer optimization. Secondly, Kriging surrogate model optimization design technology is introduced: sample data are generated via Latin hypercube experimental design to construct the surrogate model, which is combined with the Grey Wolf Optimization (GWO) algorithm for global optimization. Experimental results show that the proposed method achieves efficient lightweight design of the antenna skeleton, with the total mass of the structure reduced by 23.55%. This study provides a reference for the efficient lightweight design of large-scale phased array antenna skeletons and other complex structures.