As the terminal form of integrated energy system, microgrid can be used as a supplement to large power grid, especially off-grid microgrid is considered to be an effective means to solve the power supply in island and remote area. Aiming at the medium and above scale off-grid microgrid with multi-type power supply such as wind power, photovotaic power, diesel generator and power storage, taking the economic operation interval of diesel generator and energy storage as the constraint, an economic operation strategy of microgrid with diesel generator and power storage as the main power supply respectively is proposed to reduce the operation cost. Through the coordinated control of multi-energy complement among wind power, photovotaic power, diesel generator and power storage, the sufficient accommodation of new energy and the economic operation of diesel generation/ power storage are achieved. After the strategy is applied, the fuel consumption per kilowatt can be reduced by the economic operation of the main power supply, and the fuel consumption can also be reduced by using new energy generation. The strategy is applied to the off-grid microgrid in an island, and the actual operation results show that the proposed economic operation strategy can operate efficiently and accurately under harsh conditions.