Abstract: Introduction In order to grasp the condition of data network intuitively and real-time, and improve the efficiency of data network operation and maintenance. Method This paper proposed a method of routing detection. By collecting the protocol information such as OSPF and BGP, it could present the exactly the same real time whole network map as the router "see", so that the link fault and the third layer routing abnormality could be detected in time. Result Based on the routing detection method, this paper proposed a model of data network monitoring and simulation system, including system architecture and data flow, etc. Conclusion The system can assist network management personnel to detect and deal with fault, record historical routing events for analysis, and test network cutting program without affecting the in-use network.