The joint operation of wind power and energy storage is beneficial to solve the problem of optimal operation of wind power in spot market environment. Based on the contract settlement rules of centralized spot market, a coordination optimization strategy of contract electricity and spot electricity considering load demand is proposed. First, an energy storage model considering the battery energy storage life is constructed. Second, the principle of contract for difference in spot market environment is analyzed. Considering the load demand in the regulation strategy of energy storage, the real-time output of wind storage integration is optimized, and based on the principle of contract settlement for difference, the ratio of contract electricity to day-ahead spot electricity is optimized with the obtained real-time electricity as the constraint. The randomness of wind power output is further taken into account, and the optimization goal is improved. Finally, the CPLEX solver is used to model and solve the problem, which verifies the effect of the strategy proposed in responding to the load demand and improving the wind power revenue.