In view of that the choice of target often pay attention to the maximum comprehensive benefits and unable to coordinate all aspects of the interest in the optimal operation of cascade reservoirs,the paper put forward the idea of optimal operation of cascade reservoirs combining with water resources compensation,which is to say to give a certain amount of compensation to water cut square. Taking Yeyu river basin as the research object ,it established the mathematical model of water joint scheduling of the largest sum of water supply,and used ant colony algorithm to solve the model, and determined water compensation scheme according to actual basin. The result indicated that the operation of Tunzhuang reservoir in upstream of river will affect the irrigation water on average in Heisonglin reservoir in downstream of river which decreases from 10.227 million m3 to 8.512 million m3,and make the assurance rate of water supply of Heisonglin reservoir irrigation area reduce 13.43%.Aimed at water compensation scheme in downstream irrigation region,it set up two recent and long-term solution so as to reach balance .The colony algorithm shows its advantages of quick computing speed and good convergene in schedule of cascade reservoir . the combination of reservoir scheduling with water compensation can greatest meet the water demand of various department and effectively solve the water contradiction in upstream and downstream of river basin and different administrative regions.The result can provide a new mode for optimal operation of cascade reservoir.