The assembling technology meets the requirements of promoting ecological civilization construction and green building development of China, and is an important direction for the transformation and upgrading of the water conservancy engineering construction industry. Combined with the case of Huangpu River Engineering Assembled Cantilever Retaining Wall Project, the key technologies such as component splitting, joint connection, waterproof construction, facade decoration， component making, hoisting and installation are studied. A set of relatively complete technology essentials in the design and construction of assembled cantilever retaining wall is proposed in order to provide the reference and guidance for the application of assembling technology in similar projects.