【Objective】In order to investigate the static characteristics and lightweight optimization of the rear axle housing of a new pickup truck vehicle,【Method】a research method combining finite element platform sim ulation and bench testing was adopted. Firstly, a finite element model with high computational accuracy was es tablished in Hypermesh software. Secondly, the stress and displacement of the axle shell under full load condi tion were analyzed using ABAQUS simulation platform, and the location of the dangerous cross-section was de termined. Subsequently, the dimensional optimization of the axle shell and the steel plate spring seat and other components was carried out through Optistruct optimization module, and then the reliability of the lightweight optimization was verified through vertical bending static stiffness bench test. Finally, the reliability of light weight optimization was verified by vertical bending static stiffness bench test.【Result】Finite element analysis results show that the dangerous cross-section of the axle housing is located in the housing steel plate spring seat and housing connection with the maximum stress and deformation of 307.20 MPa and 1.440 mm. Size optimiza tion of the axle housing weight decreases from 59.07 kg to 52.55 kg and the weight reduction rate is 11.04%. The stress rises to 310.10 MPa, but it is still less than the yield strength of 45 steel of the axle housing material, which is 355.00 MPa, and the deformation is less than the standard 1.400 mm. The results of the bench test show that the axle housing passes the vertical bending static stiffness test, and conforms to the standard of the automo bile drive axle bench test.【Conclusion】The established finite element model has high accuracy, and the simula tion results are highly close to the results of the bench test. The axle housing optimized by Optistruct has good mechanical behavior performance, and the module has high reliability in axle housing lightweighting.