Abstract: The joint scheduling optimization of water works group in urban river network areas is a complex system, involving numerous water projects such as floodgates, pumps, and weirs. It is a complex nonlinear optimization problem with multiple time periods, objects, constraints, and objectives. This article proposes a multi-objective joint scheduling optimization model for water works groups aimed at improving the water environment of river networks. The coupling method of "water quantity and quality model-optimal scheduling model-optimal solving algorithm-scenario optimization method" is comprehensively used to construct a multi-objective joint scheduling optimization model for water works groups aimed at improving the water environment of river networks. The EM-MOPSO algorithm is used to solve the optimization model, and the AHP-TOPSIS based joint scheduling scheme optimization to achieve optimization and decision support for the joint scheduling of water works group in river network areas. Numerical experiments and case analysis of key optimization model technologies are carried out in a river network of a city in the Yangtze River Delta region. The results show that compared with the conventional scheduling method of water engineering, this optimization model can reduce the ecological water diversion of the river network by 23.9%～28.5% and improve the water quality compliance of the river network by 11.8%～90.4%. The optimization model can support significant comprehensive benefits such as flood control, water resource allocation, and water environment improvement in plain urban river network areas.