Aiming at the problem of quantifying the carbon reduction effect of the application of green and low-carbon technology,combined with the expansion project of a container hub port in Hainan,the carbon reduction effect analysis and research on the key technology of digital intelligent construction of large caisson gravity wharf are carried out.The carbon emission factor method and inventory analysis method are used to build the carbon emission calculation model,and the difference of carbon emission between traditional process and digital intelligent process is compared.The analysis results show that the three core technologies adopted by the digital intelligence technology,namely,the underwater riprap and leveling integrated construction,the integral hoisting of caisson prefabricated reinforcement and the caisson intelligent floating installation,have achieved 364.46,441.28 and 206.69 tons of carbon reduction during the construction period respectively.The average carbon reduction rate of direct carbon emissions from key processes reaches 16.92%,and the carbon reduction rate of purchased electricity exceeds 13%.The technology system can significantly reduce the carbon emission intensity of caisson wharf construction stage,provide a reproducible systematic solution for the green construction of gravity wharf,and has practical value for promoting the realization of carbon neutrality goal in the water transportation industry.