The utility model discloses a power supply optimization system of a distribution line. The power supply optimization system comprises at least two transformer substations, every two adjacent transformer substation are connected through the distribution line, pole-mounted switches are arranged on the distribution line, the distribution line is composed of a main distribution line and a backup distribution line, the main distribution line is connected between the two adjacent transformer substations, and the backup distribution line blocks power transmission between the two adjacent transformer substations in the normal state. When one transformer substation fails in power supply, the backup distribution line is connected, and the other transformer substation supplies power. When the main distribution line supplying power is at failure, failure points are isolated, load is rapidly transferred by optimization of the backup distribution line, power supply to user equipment is restored, and economic loss of important load is avoided.