Research conclusions:(1)Sound absorption controlled the noise pollution in the propagation path. However, metro noise control should take track system，rolling stock，tunnel，viaduct structure into consideration. Then，different bands of noise could be controlled to meet various environmental function requirements.(2)According to the advantages of porous sound absorbing materials，resonance sound absorbing materials，special sound absorbing structures and so forth， multi-layer structure and some other new structures of sound absorbing materials could be developed in future. (3)The noise absorption effect of the sound-absorbing panels could be improved by redesigning its surface structure， such as setting groove，shearing ramp and the like. (4)It is easy to boost the overall sound absorption effect to install sound-absorbing panel aside the rail and noise barrier near the track and locomotive.(5)The research results can provide the references for the study of sound absorption in urban metro.