Topology discovery method based on HSR protocol network

The invention discloses a ring network topology discovery method, which comprises the following steps of: receiving an HSR protocol-based monitoring frame sent by a second network node through a first redundant port of a lower physical layer supporting the HSR protocol, and updating the hop count and the receiving port number in the monitoring frame to obtain the updated monitoring frame; sending the updated monitoring frame to an adjacent network node through a second redundant port of a lower physical layer supporting an HSR protocol, and uploading the updated monitoring frame to an MAC layer through a network link interface; and identifying the topological structure of the ring network according to each monitoring frame uploaded to the MAC layer by each network link interface. The self-discovery of the HSR ring network topology structure can be completed by means of some fields in the HSR protocol monitoring frame, and the discovery of the physical layer HSR ring network topology structure can be realized