Concrete is a widely used building material that can be prepared using a variety of solid waste. In this study,fly ash ceramsite was used as lightweight aggregate,and cement-fly ash-silica fume-coal metakaolin was used as composite cementitious material to prepare fly ash ceramsite lightweight concrete for sound barrier. The mechanical properties,sound absorption performance and carbonation resistance of fly ash ceramsite lightweight concrete were studied. The results show that when the total content of fly ash-silica fume-coal metakaolin is 10% of total mass of cementitious materials,the mechanical properties and carbonation resistance of samples are improved,and the sound absorption performance is reduced. With the further increase of fly ash-silica fume-coal metakaolin content,the mechanical properties and carbonation resistance of samples decrease,and sound absorption performance increases. The sound absorption coefficient changes little at 1 500 Hz and below,and the sound absorption effect is the best at 2 000 Hz. The average sound absorption coefficient of sample is 044~0.58,and the noise reduction coefficient is 0.74~0.89.