With the use of Xinglong Hub’s water storage,the riverbed of the downstream section of the hub undergoes scouring along the waterway,and the water level decreases to varying degrees under the same discharge.To determine the lowest navigable water level designed for the 2,000-ton level waterway regulation project of the Xinglong to Caidian section of the Han River,the paper uses the comprehensive duration curve method to calculate the navigable discharge of the waterway design,determine the lowest navigable water level of the waterway design through the recent water level-discharge relationship and the water surface gradient during the dry season.Based on the trend of changes in the navigation water level,the paper proposes the terrain,design discharge,water level-discharge relationship adjusted according to erosion and sedimentation changes in the later stage to conduct real-time review and adjustment of the designed lowest navigation water level,ensuring the rationality of the design water level after the water level drops.