Abstract: The static load test of cast-in-place pile and carrier pile composite foundation was carried out on a residential construction site of silty clay in southern of shaanxi province.Combined with the theoretical calculation of empirical method,this paper compares and analyzes the advantages and disadvantages of the two schemes from bearing capacity and construction cost.The results show that the load-settlement curve of the two schemes also belongs to the slowly variation curve,indicating that both schemes can provide higher bearing capacity; When the length of the carrier pile is longer than 10 m and is used as the reinforcement of composite foundation,the expanded head benefit of pile tip resistance is not considered in the calculation process of empirical method,and the calculation result is obviously lower than the field test result.Under the same construction cost,the composite foundation of the support pile can provide higher bearing capacity than the cast-in-place pile.In the similar silty clay area of southern shaanxi,it is suggested that the composite foundation scheme of support pile should be taken priority.