Aimed at the characteristics of flood control projects about reservoirs and based on the spatial information processing technology,a kind of intelligent decision system for reservoir flood control is proposed in order to improve the flood control capacity and reduce the loss of flood disaster .The decision-making process of this system is analyzed and the general structure and the function of this system are elaborated.This system can effectively realize the human computer interaction , take the advantage of the experts and computer and make the best decision quickly and accurately.