The invention relates to a series compensation optimization configuration method of a power system circuit, and belongs to the technical field of power system running. The series compensation optimization configuration method comprises the steps of firstly, building a power network mathematical model; secondly, determining a power flow algorithm of a power system; thirdly, adding series compensation to the system circuit, building a multi-target optimization model with minimum system network loss and optimal voltage quality on the basis of power flow calculation by taking series compensation number, a series compensation circuit, series compensation degree and active power output of a power generator as constraint conditions, and optimizing series compensation configuration in the system by employing random weight-based improved particle swarm algorithm to achieve selection of the series compensation configuration number, the series compensation configuration circuit and the series compensation degree under optimal power flow steady state; and finally, performing simulation and solving in Matlab. By the series compensation optimization configuration method, the problem of series compensation configuration of the circuit is solved, the system network loss is reduced, and the system voltage quality is improved; and moreover, with the adoption of the random weight-based improved particle swarm algorithm, the optimal solution of the system is ensured, and local optimization is prevented.