Abstract: Flash flood disasters triggered by extreme rainstorms are highly sudden and difficult to predict,often leading to mass casualties and posing a significant threat to the safety of life and property in mountainous regions. A scientifically sound emergency evacuation plan is key to improving the effectiveness of flash flood risk avoidance. Enhancing the efficiency of emergency evacuation and reducing casualty rates through the simulation of flash flood emergency evacuation has become a critical issue in flash flood disaster research. This study takes Liucun Town,Changping District,Beijing,as the study area. By coupling the InfoWorks ICM hydrodynamic model and the Loss of Life Simulation Model(LSM),the relationships among flood velocity,water depth,building characteristics,and the stability of different population groups were established. The study simulates the changes in the states of death,fall,and safety of personnel during flood propagation,and analyzes the effects of warning lead time,road disruptions,and shelter placement on evacuation efficiency. The results show that for villages with multiple evacuation routes and optimizable shelter locations,adding risk evacuation points in suitable areas and implementing temporary closures of dangerous road sections prone to flooding can significantly improve the success rate of personnel evacuation,with a maximum increase of 55%. However,for villages with only a single road,early warning strategies are required to improve evacuation success rates.