Abstract: To address the lightweight design requirements of large-scale phased array antenna skeletons, an optimization model is 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, firstly, a hierarchical optimization design scheme based on the structural characteristics of the antenna skeleton is proposed in this paper, reducing the problem-solving dimension through layer-by-layer optimization. Secondly, Kriging surrogate model optimization design technology is introduced, and the sample data are generated via Latin hypercube experimental design to construct the surrogate model. Finally, grey wolf optimizer (GWO) algorithm is adopted 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.