The invention provides an active distribution network united planning method based on an active management mode. The method comprises the steps that (1) the access capacity and the new branch capacity of a distributed power supply are used as optimization variables to carry out chromosome coding, and an evolutional algebraic threshold value is set; an initial population is randomly generated according to the constraints of distributed power supply constant volume programming, and an evolutional algebra is set to 1; (2) the comprehensive cost of the planning scheme corresponding to each chromosome in the current population is calculated; whether the current evolutional algebra reaches the evolutional algebraic threshold value is judged, and if so, the planning scheme of the lowest comprehensive cost is selected and used as the final active distribution network joint planning scheme to end, otherwise a next step is carried out; and (3) chromosomes in the current population are selected, crossed and mutated to acquire the next generation of population; the evolutional algebra is added with 1; step (2) is back. According to the invention, the running cost of a planned distribution network is determined by considering the active management mode of the active distribution network; the method is in line with actual operation; and the scheme is reasonable.