Since the operation of Xinglong Hub on the Han River,the riverbed under the dam has been severely eroded,and the lowest navigable water level downstream has decreased significantly during the dry season.To ensure the safe operation of Xinglong Hub,the normal water storage level of the Hub needs to be lowered synchronously to adapt to the decrease in water level below the dam,resulting in insufficient threshold water depth for the upper and lower locks of Xinglong Shiplock during the dry season,and low navigation guarantee rate for ships of 1 000-ton.In response to the problem of water level changes caused by riverbed erosion under Xinglong Hub Dam,this paper analyzes the current hydrological and sediment characteristics and dry water hydrological situation of the Han River,and uses one-dimensional and two-dimensional long series annual water and sediment mathematical models to rolling calculate the riverbed erosion and sedimentation and water level changes under Xinglong Dam for 60 and 50 years.It is found that the water level corresponding to the same flow rate under the dam gradually stabilized after 40 years,considering the implementation of the 2 000-ton waterway regulation project and the annual decrease of 0.1 m in water level at Hankou Station,the water level under Xinglong Hub Dam may decrease by 3.77 m by the end of 50 years.The aim is to provide reference for the determination of the design water level of the relevant engineering projects in the section under Xinglong Dam of the Han River.