Abstract: The hilly region in Inner Mongolia is prone to flash floods during short-duration heavy rainfall events. However, the scarcity of hydrological data for small watersheds has posed significant challenges for flood forecasting in this area. This study conducts an integrated analysis of all small watersheds in Inner Mongolia and re-divides 5 935 watersheds as analysis units for flood forecasting, analyzes the flow generation and confluence characteristics of each watershed according to different underlying surfaces and climatic conditions, and focuses on distributed hydrological model clusters analysis and research on watershed floods. The Xibe River pilot watershed is selected for application and analysis, demonstrating accurate flood simulation and forecasting within this test area and meeting the requirements for watershed flood forecasting and early warning. The findings of this study can be gradually applied and promoted within the Inner Mongolia region, providing a scientific basis for flood control and disaster reduction efforts in the whole region.