The technical scheme provided by the invention includes the steps of acquiring the topology structure of a distribution network; solving a pre-established optimal configuration model by adopting a genetic algorithm based on the topology structure of the distribution network to obtain an optimal solution; and acquiring the position, type and quantity of filtering devices required to be installed based on the optimal solution. The optimal configuration model is constructed by taking the construction of the filtering device type and installation information determined by the optimal loss of the distribution network as an objective. The filtering devices include active filters, passive filters and passive and active hybrid filters according to the type. The technical scheme provided by the invention combines the genetic optimization algorithm, network harmonic power flow analysis and comprehensive optimization design of passive and active filter bank parameters, can effectively suppress harmonic waves and enables the total investment cost of the filtering devices to be low.