In this paper, a new energy storage economic dispatch strategy is proposed. Firstly, the equivalent life of a battery is evaluated based on its discharge of depth, and the optimal operation state of the battery is determined. Then, a mathematical model of double battery packs operation is established, which can make the battery closer to the optimal operation state. According to different demand of power supply, two dispatching strategies are proposed. The first strategy considers the reliability of power supply and maximum wind and photovoltaic energy consumption, and the second strategy considers the life of battery energy storage itself. The simulation operations in IEEE33 bus system. And it results show that the above two strategies can prolong the battery life, reduce the energy storage cost, and bring more benefits to the energy storage system. The second strategy gains more benefits because of more consideration of energy storage itself. Therefore, energy storage equipment, as an auxiliary service equipment, can make the price differentials between purchase and sale of electricity lower. So the price more flexible when it gains profits by purchasing electricity at a low price and selling electricity at a high price. KeywordsEnergy storage strategy • Depth of discharge ( D oD ) • Rain-flow-counting method • Equivalent life • Double battery pack • Optimum operation state * Yubo Wang