The large-scale wind power penetration has brought new challenges to the optimal power dispatch of power systems. In this paper the inherent association between the wind power scenarios'selection and active power dispatch is considered and a wind power scenario self-adaptive selection method is presented.This method is able to dynamically adjust the power range of each scenario according to the active power adjusting ability.On this basis，an active power dispatch model for wind power connection is proposed based on the scenario analysis method.By a comparison of the conditional expected re-dispatch costs of different selected scenarios，the impact of the wind power scenario selection method on active power dispatching is analyzed. Case studies show that the model and method presented can yield an active power dispatch scheme better adapted to wind power uncertainty.