Abstract: In order to reduce the noise influence of gas turbine during operation, a box-mounted body panel with wide frequency and high sound insulation capability is designed in this paper. The simulation model of the box-mounted body panel is established using the finite element software COMSOL, and the transfer matrix method is used to verify the correctness of the model and reliability of the calculation. By combining with the simulation results, this study investigates the influencing rule of each structural parameter on sound insulation performance and analyzes its intrinsic sound insulation mechanism. The Nelder-Mead algorithm is introduced in detail, and based on that, it is utilized to optimize the structural parameters of the box-mounted body panel. The final designed box-mounted body panel demonstrates excellent sound insulation performance across the entire calculated frequency range.