Abstract: To characterize flood-risk responses in the Qingtongxia–Shizuishan reach of the Yellow River in Ningxia and quantify variations in inundation metrics and land-use exposure with peak discharge, a two-dimensional hydrodynamic model covering approximately 207 km was developed using the Anlan Simulation System. The model integrated a digital elevation model, surveyed cross-sections, observed discharge records from 1950 to 2022, and land-use data. Historical typical floods and design floods with return periods of 5–100 years were simulated to assess flood inundation, comprehensive risk, and response sensitivity. The inundated area ranged from 265.09 to 319.21 km2 under the historical-flood scenarios and from 458.75 to 480.81 km2 under the design-flood scenarios, with high-risk zones accounting for more than 80% of the inundated area under the latter scenarios. From the 5-year to the 100-year design flood, peak discharge increased by 82.75%, whereas inundated area, mean water depth and maximum flood velocity increased by less than 5%. These results indicate that levees and floodplain–channel topography constrain the expansion of inundation and weaken the responses of major hydrodynamic metrics to increasing peak discharge. The increase in flood risk is mainly reflected in longer inundation duration and earlier flood arrival. The findings provide technical support for flood-control planning, floodplain land-use optimization, and emergency risk management in the study reach.