In the background of rapid wind power development and its large-scale integration into the power grid in China， combining the wind power operating characteristic and the power grid safety demand， a principle of hydropower annual operation mode is proposed in the large-scale wind power integration. The mathematical model of hydropower operation and dispatching is established by considering the contribution of hydropower peak load regulation for the wind power integration. Taking Huairen Hydropower Plant in the Northeast China power grid as an example， the hydropower annual operation modes are calculated for different water incoming modes. The simulation results show that the method is beneficial for increasing the ratio of allowable clean energy in the power grid.