The invention relates to an automatic switching method of a remote standby power supply. The automatic switching method of the remote standby power supply comprises the steps of: respectively decoding an IEC61850-9-2 message emitted by a different interval merging unit and a GOOSE message emitted by an intelligent control unit through a plurality of network input and output processing modules of a station domain intelligent control host computer, forming the information such as bus voltage and switch position of the current station, the bus voltage and lock signal of the adjacent station; judging whether the bus of the adjacent station is decompressed, if so, judging that the bus voltage and the switch position of the current station are normal and no lock signal of the adjacent station appears; and switching on the switch between the current station and the adjacent station, so as to supply power to the adjacent station by the current station. By adopting the automatic switching method of the remote standby power supply, reliable power supply of one transformer substation to the adjacent station can be achieved in a regional power grid; and the reliability of power supply of a power grid is improved.