The invention discloses an installation position and capacity optimization planning method of an electric energy quality compensator. The optimal installation position of the compensator under the condition that the capacity is deterred can be calculated by Newton-Raphson algorithm-based particle swan optimization according to harmonic and a reactive power parameter of each node in a microgrid, meanwhile, the characteristic of discretely-distributed capacity of the compensator is considered, the optimal compensation capacity of the compensator is obtained by a cutting plane method, and thus, the economic running of the microgrid can be achieved by the obtained installation position and the capacity of the compensator.