In view of the difficulty of PHC pipe pile sinking under complicated geologic condition，we determine the structural type of PHC-steel pipe composite pile based on an official ship wharf project in Sanya and combined with the advantages of PHC pipe pile and steel pipe pile and relevant industry specifications. According to the characteristics of PHC-steel pipe composite pile，from the perspective of penetrating thick sand layer，we propose the ultimate bearing capacity state of wharf structure by structural calculation software and related specification formulas. Analyzing the results of structural calculation，stress characteristics and pile foundation test，we put forward targeted pile foundation improvement measures and pile sinking control conditions，and obtain the PHC steel pipe composite pile meeting the engineering design requirements. The results show that the PHC steel pipe composite pile method meets the requirements of bearing capacity and strain of pile foundation，when penetrating the thick sand layer，the PHC-steel pipe composite pile is feasible and reasonable in economy.