The utility model discloses a secondary relay protection chip of an intelligent substation. The secondary relay protection chip comprises an HSR switching module. The HSR switching module receives message data of equipment of the intelligent substation transmitted by the Ethernet physical layer interface module through the HSR MAC interface module; and the message data is classified, time sequencecontrol and transmission are carried out according to the priority of the message data, and the types of the message data include an MMS network message, a GOOSE network message, an SV network message and an IEEE1588 network message. According to the secondary relay protection chip, the functions of analyzing, classifying and the like of various existing data of the intelligent substation are realized through an Ethernet data channel established by an independent HSR module; therefore, each layer of equipment of the intelligent substation is convenient for simplifying network design, reducingequipment power consumption and cost, enhancing reliability of a single set of equipment, simplifying engineering field network architecture and construction difficulty, improving system integration,and improving reliability and maintainability of system operation.