In order to deal with the shortcomings of static economical dispatch for microgrid ignoring the inherent link between the intervals，by considering the influence of wind turbines，photovoltaic cells and sodium sulfur battery on economical operation，and with micro power output and power operation minimum cost as objective function，a dynamic economical dispatch model for microgrid is proposed.A VC++ procedure for microgrid dynamic economical dispatch using the improved differential evolution algorithm is compiled.By improving the parameters set of the algorithm，the convergence speed and ability of preventing the algorithm from falling into local optimum are enhanced.According to the characteristics of the microgrid structure of calculation，the grid-isolated/grid-connected mode operation output principle of the micro-source and control strategy of typical microgrid structure are formulated.The results show that the dynamic economical dispatch model for microgrid has more advantages than static scheduling in cost saving，and is more global and practical for sodium sulfur battery charge and discharge.