To combine the real-time run-off information and digital analysis system of water distribution network, and realize the real-time simulation and dynamic analysis for water distribution network, an urban water distribution network real time simulation system based on OPC communication of SCADA system was built up in this paper. Using SCADA software for OPC communication, the real-time operation information for water distribution network was gained. The simulation model was driven by real time monitoring flow and pressure data to simulate water distribution, to display pressure results online and to alarm pressure. The abnormal operation scenario could be detected in real time. The simulation system solved the problem of data input and user interaction of traditional network model, and offered a new idea for the development of intelligence water network.