Abstract: The early warning thresholds for flash flood disasters serve as the cornerstone of flash flood prediction and early warning systems.Currently, China predominantly relies on empirical methods and water stage-discharge backward extrapolation method to establish rainfall thresholds for early warnings.Additionally, there is a gradual shift towards adopting composite threshold and dynamic critical threshold approaches.In light of a comprehensive assessment of commonly used rainfall threshold analysis methods both in China and abroad, future research should prioritize modifying existing techniques.Specifically, attention should be directed towards accounting for the spatio-temporal variability of rainfall events, high-concentrated sediment flow, debris flow, and other uncertain factors.