Abstract: The substation full-stop transfer supply method suffers from the defect that the main substation load ratio cannot meet the actual operation needs. A substation full-stop transfer supply method based on tree topology is designed to solve the above problems. The maximum load supply of the substation is extracted, the current working efficiency of the substation and the corresponding load supply potential are deduced, the means of self-feeder restoration and combined contact switches are adopted, the calibration process of load transfer is developed in combination with evaluation indexes, the load transfer calibration model is improved, the direction and state of the topology is guided by using tools such as heuristic search algorithms, and a hierarchical full-stop transfer supply model is constructed based on the tree topology. The optimization model is based on a tree topology. Experimental results: The average values of the main substation load factor for the substation full stop diversion method in the paper and the other three substation full stop diversion methods are: 70.986%, 60.278%, 62.684% and 63.030% respectively, proving that the substation full stop diversion method in the paper better meets the main substation load factor of 70% when combined with the action principle of tree topology.