Abstract: Automotive lightweighting technology can effectively reduce energy consumption, reduce emissions and improve safety. An automotive wire harness bracket modeling case is presented in this paper. After lightweight modeling of the automotive wire harness bracket using spatial dimensional parameters, the lightweight design results are obtained based on two different plastic materials using an advanced derivative design derived from an iterative algorithm, after the basic design structure, load conditions and manufacturing methods are determined. The results of the derivative design are 71.57% and 74.38% lighter respectively while meeting the range of mechanical properties and safety factors. This shows that the incorporation of derivative design in the design process can achieve innovative lightweight design of automotive parts, which is an inspiration for the lightweight design of modern vehicles.