The concrete cofferdam structure is stable,occupies a small riverbed area,and has good anti erosion effect.It is widely used in the construction organization and design of hub stage diversion.However,it faces difficulties in later demolition,difficulty in removing demolition waste,and significant impact on surrounding buildings.This article focuses on the impact of longitudinal cofferdams construction on discharge capacity of the Yakou Shipping Hub in the Han River.CATIA software is used for three-dimensional numerical simulation,and flow field,discharge capacity,and water level effects are analyzed on the retention and removal plans of longitudinal cofferdams under different characteristic flood flows.This provides a scientific basis for the selection of retention and removal plans for longitudinal cofferdams.The results show that retaining the longitudinal cofferdam will reduce the water flow velocity and discharge capacity of the adjacent area’s discharge gate hole,increase the height of the central blockage of the river to a certain extent,but still meet the requirements of the hub discharge capacity control standard.After safety and stability review,the longitudinal cofferdam can be retained,providing experience reference for the construction organization design of similar hub projects.