Abstract: Under the background of global warming, extreme flood disasters have become more frequent, with their impact especially pronounced in the arid and semi-arid regions of the Yellow River Basin. To enhance the capability in defending flood disaster in arid regions, this study focuses on the Ten Watershed in the upper reach of the Yellow River. This study primarily employs the Hydrologic Engineering Center's River Analysis System (HEC-RAS) as the main research tool and uses model simulation results and Sentinel satellite observations as the main data sources. This study conducts detailed process simulations of typical torrential rain flood events in the area and evaluates their effects on flood event simulations. The main findings of this research include: (1) Validation based on Sentinel images shows that the hydrodynamic model can simulate flood inundation with a relatively high accuracy; (2) The resolution and quality of the Digital Elevation Model (DEM) are vital for the accuracy of the simulated flood inundation extent; (3) HEC-RAS still has considerable limitations in simulating floods in large basins using high-resolution DEMs and computational grids. Additionally, this study suggests that the region should strengthen hydrological monitoring efforts to provide ample data support for establishing an integrated flood defense system in the future.