For the grid connection of a large number of distributed generators, the topology of distribution network has changed, which has seriously affected the stability of power system. An improved Kruskal algorithm and improved Broyden-Fletcher-Goldfarb-Shanno (BFGS) algorithm are combined for distribution network fault reconfiguration with distributed generation, with the minimum network loss and minimum switching times as the objective function. When the distribution system fails, the improved Kruskal algorithm is used to divide the isolated islands, and the distributed generators that can supply power independently are divided into isolated islands to reduce the power loss load as much as possible, the off island distribution network adopts the improved BFGS algorithm for off island reconstruction. The simulation results show that compared with the previous reconstruction, this method can effectively reduce the active power loss, and the single-branch and multi-branch faults are reduced by 97.268 3 kW and 89.545 8 kW, the minimum voltage of the system node has been increased by 0.039 0 p.u. and 0.039 0 p.u., and the number of switching operations is 3 times and 4 times, respectively.