The part uses Bi-directional Evolutionary Structural Optimization (BESO) to obtain a topology with superior performance, and the entire optimization-design process is controlled by a parametric process, with a high degree of automation and convenient and precise control of local details. The final part adopts a hollow lattice filling structure with a wall thickness of 3.5mm, which is 20% lighter than the hollow die-cast aluminum alloy of the original scheme, avoids the local discontinuous corner caused by the process limitation, and is integrated formed by BLT-S815. The strength and stiffness of the formed parts meet the needs of use.