In order to improve the economical efficiency of micro-grid, it is necessary to conduct the day-ahead optimal scheduling. In this paper, a micro-grid optimal scheduling model is established for minimizing the operation cost of the micro-grid. The optimization variables of this model includes the battery charge/discharge power and fuel cells output power. Based on the day-ahead predicted data, one day is divided into 24 hours and the the scheduling period is set as 1 h. Then, taking 15 minutes as a period and the day is divided into 96 scheduling periods. The results of the one hour optimal scheduling are taken as the input of the 15 minutes optimal scheduling for re-optimization. The several heuristic algorithms are used to solve the models, respectively. The results show that the improved black hole algorithm converges faster than the others. The optimal results can be utilized as a reference for the battery charge/discharge power and the fuel cells output power for the next day. This method can effectively reduce the operating costs of micro-grid.