Network redundancy fault tolerance method and system based on IP protocol expansion

The invention relates to a network redundancy fault tolerance method and system based on IP protocol expansion. The method includes the steps that a transmitting terminal receives a data packet sent by a transmission layer, whether the data packet belongs to redundancy communication or not is judged, the data packet is processed through the IP protocol expansion network redundancy flow if the data packet belongs to redundancy communication, the data packet is processed through the protocol stack normal flow and sent through a link layer if the data packet does not belong to redundancy communication, a receiving terminal receives the data packet, duplication eliminating is conducted if the data packet belongs to redundancy communication, and the data packet is normally received through a protocol stack if the data packet does not belong to redundancy communication. On the basis of expanding the IP protocol, the method is achieved completely on the basis of software without relying on special devices, no requirements for the network topology exist, the 0 delayed switching characteristic exists when a single link fails, and the requirements for the high real-time performance and reliability of data communication in the fields of intelligent substations and the like can be met.