Aiming at the problem of low frequency （500~2000 Hz） noise absorption in the tire， a combined sound absorption struc? ture is designed， which is composed of porous material and coiled-up cavity structure. Combined with the sound absorption princi? ple of porous material and coiled-up cavity， the theoretical analysis model of the combined sound absorption structure is estab? lished， and the expression of the sound absorption coefficient of the model is deduced. The sound absorption performance of the combined sound absorption structure in the middle and low frequency range is analyzed by using the finite element method. The re? sults show that the sound absorption performance of the combined sound absorption structure is good in the frequency range of 500 Hz to 2000 Hz， and the sound absorption peak appears around the frequency of 1092 Hz， which is close to perfect. Compared with the single porous material， the sound absorption performance of the combined sound absorption structure has been greatly im? proved. By changing the volume proportion of porous materials in the combined structure， the change rule of sound absorption per? formance is studied. The sound absorption mechanism of the structure is analyzed by plotting the complex frequency plane distribu? tion of reflection coefficient and combining with the acoustic impedance matching condition. Then the combined sound absorption structure is tested in an impedance tube， and the correctness of the theoretical analytical model and the finite element model is veri? fied. Finally， the combined sound absorption structure is superimposed on the felt wheel cover material， and the sound absorption performance of the superimposed structure is studied， and the measures to further improve the sound absorption performance are proposed. The peak sound absorption frequency of the combined sound absorption structure can be adjusted according to the vol? ume proportion of the porous material， and the overall thickness is small， so it has certain application effect in the low frequency noise control of tire.