To reduce the number of the infeasible solutions produced in the distribution network reconfiguration process, reduce the number of iterations in distribution network reconfiguration，and improve its computational efficiency, the genetic algorithm in this paper is improved: regard the number of 1 in a certain chromosome code as the equivalent length of the chromosome segment, during cross, let the chromosome segments which have an equal equivalent length to cross; In the mutation process, use the method of making randomly assigned disconnect switch point to mutate, while no longer to mutate blindly. At the same time, use the breadth-first search algorithm to judge the feasible solutions, and finally use the IEEE33-bus test system as an example to validate, find the result is reasonable, the number of iterations is less, and the convergence speed is faster, proving the improved genetic algorithm proposed in this paper is effective.