Ring network power supply refers to two or more feeders in different substations or different substations in the same substation, which are connected to each other in a loop to supply power. After the distribution network circuit realizes the ring network power supply, it greatly improves the existing single-supply power supply defects and realizes the interconnection and power supply of the branch trunk lines. The greatest advantage lies in the rational allocation of the power load, shortening the power supply radius, and comprehensively improving the quality of the user-end voltage. Moreover, when a certain part of the line fails, it is possible to isolate the fault part in time and try to switch the load from both sides to the normal load. This avoids a large-scale blackout of the power grid, shortens the repair time, and reduces the loss of blackouts.