Abstract: During the launch and flight of carrier rockets, the acoustic and vibration excitations generated by the external environment may pose threats to the internal payloads. Porous materials, as lightweight sound-absorbing materials, have been widely used in research related to noise reduction and vibration damping of fairing structures. This paper combines the physical model of porous materials and impedance tube experiments, and employs particle swarm optimization algorithm to conduct parameter fitting and acoustic performance optimization of porous materials. A multilayer porous material optimization design method is proposed, and its sound absorption performance is validated through experiments and simulations. Based on the scaled model experiment platform of the fairing cylindrical section, the noise reduction and vibration damping performance of the multilayer porous material acoustic cover layer are verified, and the influence of porous material laying position and laying rate is analyzed through simulation, providing design guidance for the application of porous materials.