Abstract: Taking Kaifeng section of Huiji River in Huai River basin for an example, HEC-RAS model is applied to simulate the process of five-year and twenty-year flood.And the information of water surface profile, velocity and levee break position is visually displayed.The simulation results show that the model is applicable for the water surface profile in plain area, meets the needs of flood control and waterlogged elimination, and also provides technical support for river regulation project.