During the construction of the intake tower project of the diversion system of Dongba hydropower works in Guangxi, China, largeface cantilever formworks construction technology is adopted, which results in good engineering efficiency in respect of high construction speed, low construction investment and good appearance quality of the structure. The working principle, main structures and key construction operation points of largeface cantilever formworks are presented in the paper, which can provide reference for the construction of superhigh mass concrete structures and other similar works in the future.