The effects of different contents of mineral admixtures including metakaolin, fly ash and steel slag, on the compressive strength of shale ceramisite concrete were studied systematically and the microstructure and composition were analyzed by SEM and XRD. The results show that the compressive strength of the concrete is the highest when the mass content of the mineral admixtures is about 10%. Then, when two kinds of mineral admixtures are added into the concrete at different ratio, the compressive strength testing shows that the concrete with 10% metakaolin and fly ash (ratio 1∶2) exhibits the best compressive strength (18.1、28.6、35MPa at 3d, 7d, 28d, respectively), which is higher than the concrete without mineral admixture by 417%、267% and 250% at 3d, 7d and 28d, respectively. The main reason is that the addition of metakaolin and fly ash can optimize the microstructure of lightweight aggregate concrete, thus, improving the strength of the concrete.