In this paper, 8μm stainless steel fiber felt was used as raw material, and the stainless steel fiber porous material were prepared by volume-weighing method and high temperature sintering with different porosity, average pore size and thickness. Positive gradient structure, inverse gradient structure and film composite structure were designed by structural optimization. The sound insulation performance of the three kinds of the structures was tested, and the sound insulation characteristics of the structures were studied respectively. The sound insulation results indicate that the stainless steel fiber porous material has a certain sound insulation performance. The thickness is 20 mm, the porosity is 85 %, and the average sound insulation of the stainless steel fiber porous material is 18.92 dB in the frequency range of 50 ~ 6400 Hz. The lower the porosity, the smaller average pore size, the thicker the thickness, the better the sound insulation performance of the material; The sound insulation performance of the designed positive gradient and the inverse gradient structures is worse than the single layer stainless steel fiber porous material. The sound insulation performance of the stainless steel fiber porous composite material with film material is greatly improved at medium and high frequencies. The thickness is 20 mm, the average sound insulation is 27.86 dB, and the highest is increased by 16.96 dB.