In response to the long-term submergence of the pile top in a pile supported wharf,the traditional cast-in-place method for pile caps has long construction periods and difficult quality control.On the basis of a certain project,the research on prefabricated structures and construction technologies for prefabricated pile caps is conducted.Through the design of pre-embedded I-beam in the pile cap,the self bearing capacity of the pile body is utilized to solve the dependence of pile cap construction on the bottom formwork and temporary support system,simplifying the construction process.By designing the pile core reinforcement cage with “steel bars+section steel”,the vertical extension of the top pile core reinforcement cage of the inclined pile into the cavity of the prefabricated pile cap is achieved,strengthening the connection strength.By using steel clamps to seal the bottom of the grouting and designing reserved grouting and drainage holes,efficient sealing grouting underwater is achieved,enhancing the overall structural integrity.The application results show that the structure and construction technology effectively overcome the influence of tidal water level,significantly reduce the difficulty and quality risks of underwater construction,shorten the construction period by about 65%,and save about 25% of manpower.