Abstract: To achieve the goal that the backup power supply can be used quickly when power system fails, a remote backup automatic switching scheme for multi-stage substations with serial power supply is proposed. The concepts of open loop substation and non-open loop substation are introduced in serial substation. The open loop substation considers in-station backup switching-in and remote backup switching-in while the non-open loop station only considers remote backup switching-in. The inter substation communication channel adopts a dual channel design, which can communicate with adjacent substations on both sides at the same time to recognize the topology position recognize the backup automatic switching device. Through real-time communication between substations and the coordination of different backup automatic switching methods, recognize can be reduced, and power supply can be restored to the maximum extent after a power system failure. The scheme has been applied to a 35 kV serial supply substation in Zibo, Shandong . The device actions under different power system faults are simulated. The experimental results verify the effectiveness and reliability of proposed scheme.