A hydrodynamic model integrated with river networks, ponler areas and the controlling of hydraulic structures was established. After validation and calibration with sufficient measured data and current situation investigation, this numerical model can successfully simulate the flood. Based on Web, GIS and database technology, the management system of dynamic flood risk maps coupledwith the hydrodynamic model was developed. Dynamic flood risk mapping can be produced after the employment of the hydrodynamic model, which can deal with multiple customized data, including precipitation, boundary conditions, parameters of hydraulic structuresand scheduling disciplines. Combined with online forecasting data, the management system can provide technical support and references for the application of flood risk maps on flood control and disaster relief, as well as flood management and forecasting in China.