Abstract: To guide the charging and discharging of energy storage devices in depth and to improve its service life, rain-flow counting method is used to analyze the influence of charging and discharging on the lifetime of energy storage device, and an economic schedule model of microgrid is built by considering the operation cost of energy storage equipment. As to such shortages as slow convergence speed and being easy to obtain partial optimization of free search algorithm(FS), chaos-free search hybrid algorithm(C-FS) is proposed to solve the optimal dispatching problem of microgrid by combing chaos theory and elitist strategy in this paper. Through the analysis on the 14-bus radial microgrid system, the results show that service life can be effectively improved by considering the operation cost of energy storage equipment. Meanwhile, compared with the traditional algorithm, chaos-free search hybrid algorithm has better fast convergence and can obtain global optimal solution.