To quantify the impact of the northward diversion water level control of lakes on dispatching performance in the Jiangsu Section of the South-to-North Water Diversion Eastern Route Project, a multi-objective joint optimization scheduling model for rivers, lakes, gates, and pumps considering this constraint(operating scheme S1) and not considering this constraint (operating scheme S2) was constructed. The goal is to minimize the comprehensive water shortage rate and total pumping volume in the receiving area, and introduce the Gini coefficient of water supply to ensure the balance of water supply in each receiving area. The results show that under the same water supply level, operating scheme S2 can significantly reduce the total pumping volume, abandoned water volume, and river pumping volume, and improve the lake’s regulation and storage capacity and water resource comprehesive utilization efficiency. In the wet year, the pumping volume of operating scheme S2 decreased by 34.9% compared to S1, the amount of abandoned water decreased by 5.9%, and the amount of water pumped into the river decreased by 34.7%. The water supply of Hongze Lake and Luoma Lake increased by 169 million m 3 and 186 million m 3 respectively, and the amount of water pumped into the lake by the pump station decreased by 85.1% and 50.3% respectively. On the premise of ensuring safe water supply to the lake, not considering the water level constraint of the lake’s northward adjustment can enhance the regional water resources guarantee capability and improve the engineering water scheduling capability.