Abstract: The dam site of Yakou shipping hub of Hanjiang River has great variation in the flow rate, and the covering layer of the riverbed is mainly silt and fine sand. Half of the initial dry period of diversion has passed, and the design of construction diversion and interception is very difficult. According to the actual situation of the project, combined with hydraulic calculation and numerical simulation analysis, the project is divided into two phases of diversion. The first phase of diversion cofferdam uses pipe bag sand and mold bag concrete to replace the traditional reinforced gabion and Reynold slope protection, and adopts pipe bag sand and block stone to stop the flow of double berm. The second phase diversion cofferdam uses pipe bag sand to protect the slope, and adopts sand pebble and block stone to intercept the flow of the double berm.