Compared with the traditional distribution network, the active distribution network (ADN) has the advantages of high utilization of distributed generation, low network loss and strong controllability, and its optimal operation is a typical multi-objective optimization problem. This paper considers peak load shifting strategy of energy storage system in smoothing load curve and healthy economy simultaneously and establishes a typical multi-objective ADN model; considering the multi-dimensional and nonlinear characteristics, this paper proposes an improved algorithm based on quantum particle swarm optimization (QPSD),which adopts the superposition state and probability expression characteristics of quantum theory to increase the population diversity and global optimization. Finally, a typical active distribution network is taken as an example to verify the feasibility of the method.