The invention discloses a distribution network optimization loss-reducing reconstruction method considering maximum power supply capability. The method comprises the following steps: firstly constructing a mathematical model of a maximum power supply capability index of a distribution network, and according to the mathematical model, evaluating maximum power supply capability indexes in different operation modes of the distribution network by adopting a variable step continuous power flow algorithm, so that the maximum power supply capability of the distribution network is obtained; meanwhile, based on a multi-scenario method and variation of different modes of the distribution network, constructing a distribution network loss-reducing reconstruction model capable of considering constraint of the maximum power supply capability index, and solving a distribution network reconstruction scheme in a set reconstruction time period by adopting a binary particle swarm algorithm based on dynamic inertia weight adjustment. The method disclosed by the invention has the advantages that power supply capability margin required by a system can be maintained while loss reduction of the distribution network is realized, and power supply reliability of the distribution network in a complex and uncertain environment is effectively guaranteed.