 The paper studied the optimization of the large-body structure of a hydraulic static pile driver using the APDL Parametric Design Language provided by ANSYS. Two optimization algorithms were used to reduce the mass of the large-body structure while meeting the required strength and stiffness. The results showed that the improved BP Neural Network algorithm based on the particle swarm optimization algorithm performed better than the other algorithm in terms of mass reduction. The optimized mass of the large-body structure was reduced from 82,556.1 kg to 65,046.15 kg, a mass reduction of 21%. This article was authored by Jean May Wu, Jiuming Hu, and Yen Ching Yang.