In view of the problem that the output forecast and load forecast of uncontrollable micro sources in micro-grid have large errors existing in the current technology, the uncertainty description model is added to the traditional micro-grid economic dispatch model, and the economic optimization results of micro-grid under different emphases are obtained and analyzed. Firstly, the interval number is used to describe the prediction uncertainty, and the concept of tolerance is derived by combining the membership function. Secondly, on the micro-grid structure of grid connected operation mode, the optimal scheduling model of micro-grid with the lowest operation cost as the objective function is established, and the model is transformed into interval number form. Finally, the particle swarm optimization algorithm and MATLAB are used to solve the above model, and the results are analyzed in detail. The scientificity and validity of the proposed model are verified by analyzing a grid connected micro-grid.