A serious shortage of freshwater resources is presented in the world today, and the desalination of sea water has become an important way to solve the global shortage of water resources. In the paper, a real time energy management strategy for isolated DC micro-grid consisting of wind power generation, energy storage system and sea water desalination system is presented based on the super short-term wind speed prediction. Firstly, in accordance with the results of super short-term wind speed prediction and the state of charge of battery, the commitment of the desalination of sea water units is proposed. Secondly a DC-link voltage coordination control scheme based voltage droop characteristic is proposed, which ensures the stability of DC-link voltage by charging or discharging the battery, limiting the power output of the wind turbine or load shedding under different operation conditions. Lastly, simulations are carried out under different operation conditions, the results testified the effectiveness of the energy management strategy.