The invention relates to a relay protection data transmission method between relay protection information systems, which is applied to a first relay protection information system. The relay protectiondata transmission method comprises the following steps: receiving an operation data request instruction, sending an operation data request message to a second relay protection information system; Wherein the operation data request message comprises a read data type; Receiving an operation data response message sent by the second relay protection information system. The operation data response message comprises an operation data file of a second relay protection information system, and the operation data file is matched with the read data type. A relay protection data transmission method between relay protection information systems according to an embodiment of the present disclosure, It can realize the efficient data exchange between relay protection information systems of different powergrids, and make the data integration between relay protection information systems of different power grids easier to realize, and is conducive to the rapid judgment of power grid faults when the power grid fault occurs.