Abstract: In order to enhance the business support ability and save economic cost of power distribution internet of things, this paper proposes an optimal deployment method of the distribution edge computing terminals for software defined network（SDN）. Base stations of power wireless private network are rich in data flow and service flow. Using the location of wireless base stations to deploy distribution edge computing terminals has significant advantages. This paper introduces the edge computing architecture of power distribution internet of things for software defined network, and establishes the models of business, intelligent terminal and edge computing terminal. Further, considering the communication mode constraints of edge computing terminal, intelligent terminal and SDN controller, and the constraints of service delay and hardware configuration of edge computing terminal, aiming at the sum of annual average equipment cost and annual average operation cost, this paper establishes an optimal deployment model of distribution edge computing terminals. Finally, the effectiveness of the proposed method is verified by the simulation results of a multi-scenario example.