Aiming at the problem that the gravity wharf built on a soft foundation has a low bearing capacity and large settlement of the foundation，we introduce the design method of DCM pile in the foundation reinforcement of gravity wharf based on the design and construction technology of the foundation treatment of the artificial island rescue wharf of a cross-sea channel in Guangdong coastal area，including the cement content and water-cement ratio of DCM pile，layout form and replacement rate，external stability checking of reinforced body，internal stability checking，circular slip，and settlement checking，etc.，and compare the calculation theories of DCM pile in Chinese code and Japanese code. The results show that the treated foundation by DCM pile has high rigidity. DCM pile treatment can effectively reduce the foundation settlement and improve the foundation bearing capacity，which is an effective way to solve the foundation bearing capacity and service period settlement of similar gravity wharf structures.