To achieve optimal configuration of switching devices in a power distribution system, this paper proposes a repulsive firefly algorithm-based optimal switching device placement method. In this method, the influence of territorial repulsion during firefly courtship is considered. The algorithm is practically applied to optimize the position and quantity of switching devices, while avoiding its convergence to the local optimal solution. The experimental simulation results have showed that the proposed repulsive firefly algorithm is feasible and effective, with satisfying global search capability and convergence speed, holding potential applications in setting value calculation of relay protection and distribution network automation control.