Abstract: The article elucidates the cenifide dispatching of hydropower station group, in which qiyi station is a mainstay, inquires into the data series of runoff and irrigation carefully and seriously, and sels up mathewatical model by means of Markovian decision theory. What is more, this paper makes a study on the characteristic of Qiyi reservoir teking, irrigation as the dominantfactor and intorduces such new techniques as parallel translation frequency carre method and treating reliability restrain with two genalty function.