The invention provides an improved particle swarm algorithm-based optimized configuration method of a distributed electrical connection power distribution system. The optimized configuration method comprises the following steps: 1, inputting optimized configuration calculation parameter data, initializing particles and the flying speed of a particle swarm and a connected distributed power factor; 2, selecting an optimized configured type, selecting an entrance according to distributed power optimized configuration scheme types, namely addressing tolerance, sizing location optimization and location optimization and tolerance with a specified access number N; 3, selecting an optimization configuration goal and recording power distribution system parameters and distributed power system parameters, wherein the parameters includ system grid loss and average voltage level parameters; 4, performing optimized configuration calculation, performing fundamental wave load flow calculation and harmonic load flow calculation under each particle to obtain the system node voltage, the system fundamental wave loss and the harmonic loss under the particle, and then calculating a system node deviation index and a system total loss index; and 5, checking and outputting the result of the optimized configuration calculation.