Abstract: As the further research of load transfer problem in high-voltage distribution network,the time-sequence of switch operation has great influence on the reliability of power supply and the safety of system.By analyzing the transfer patterns,a risk evaluating method is proposed based on the transfer principles and the risk measuring matrix is built up which is similar to the distance matrix in travelling salesmen’s problem（TSP）.The improved ant colony algorithm is used to solve the timesequence problem of switch operation.Load transfer cases of high-voltage distribution network in a city are used to test the method,and several strategies have been obtained for different operational situations.By comparing with enumeration method and empirical method,the proposed strategies are proved effective.