The vibro-replacement stone columns are mainly used to treat the shallow-layer soil and generate one kind of composite foundation in order to reinforce the bearing capacity of the foundation,decrease the settlement and eliminate the sand liquefaction.The CFG pile is settled at the centroid of four gravel columns and the tip of the CFG pile is deep in the hard layer,which plays an important role in controlling the bearing capacity and the displacement of the composite foundation.This paper researches the composite foundation consisting of the vibro-replacement stone columns and the CFG piles before and after the treatment by the static sounding test,the dynamic sounding test and the static load test.The results indicate that the vibro-replacement stone column in the combined-pile composite foundation largely increases the bearing capacity of the single CFG pile and the soil layer,and the smaller the distance between piles,the greater the strengthening effects will be.