A real-time energy management strategy is proposed for islanded operation microgrid system consisting of diesel generators, photovoltaic generation, energy storage devices and load. Data of energy storage devices monitored in real time are used to forecast the state of energy for next time. Considering different payload power, corresponding scheduling strategies are used. Diesel generators as backup power is normally closed. The energy storage devices as V-F supported units do not accept the power dispatch, which absorb surplus power in microgrid automatically by leaving a sufficient adjusting margin. The energy storage devices as non-V-F supported units receive power commands to participate in load power supply. Diesel generators will be turned on in advance by considering the planned start time to ensure uninterrupted power supply for load when energy storage devices’ state of energy approach to the lowest limits. Then energy optimization model is established after diesel generators put into operation. Finally, experiment results indicate the reasonableness of the microgrid dispatch strategy proposed, which provides guidance and reference for the energy management strategy of stand-alone microgrid system applied to the actual projects. This work is supported by the Intoroduction of Innovative R & D Team Program of Guangdong Province (No. 2011N015).