The construction technology of cementitious sand gravel is to use cementitious sand gravel as the combined structure of anti-impact and anti-seepage in cofferdam engineering to replace the structural type of traditional anti-seepage wall + block stone cladding.Aiming at the application practice of the year-round cofferdam project of the right bank lock of the second phase of the Longxikou Navigation-power Junction project in Minjiang River,the selection of raw materials and matching ratio,construction technology and method,quality control,etc.,are introduced,and the construction technology of the existing structural connections such as cemented sand gravel and concrete,high-spray impermeable wall and construction seams in the application process are mainly expounded,and the construction technology and economy are compared.The results show that the construction technology of cementitious sand gravel has the advantages of simple construction process,less process,low cost and fast construction speed.