The invention discloses a reservoir group combined operation scheduling system and method for improving a river and lake relationship. The system is characterized by comprising a hydrological information acquisition module, a reservoir working condition access module, an information transmission module, a data preprocessing module, a river and lake relationship scheduling and decision-making module and a display terminal module. By the system and method, shortcomings of an existing reservoir scheduling technique are overcome so as to realize the objective of benefiting both rivers and lakes, the river midstream-upstream and river-communicated lake reservoir group combined operation scheduling system and method is in favor of improving the river and lake relationship, multi-objective optimal regulation and control is carried out aiming for controlled hydrology and water ecological parameters for representing the river and lake relationship, and cross-basin, multi-objective and integrated water conservancy project group remote combined regulation and control in favor of improving the river and lake relationship is realized.