The groundwater in the foundation pit near the river has the characteristic of decreasing water level with increasing distance from the river. In the foundation pit dewatering project, the uneven distribution of groundwater before and after will waste a lot of construction costs due to the traditional equidistant arrangement of dewatering wells. Therefore, based on the foundation pit project of Nanqiao Flood Diversion Sluice Hub in Handan City, and based on the funnel theory of dewatering wells and the principle of group well superposition effect, the layout of dewatering wells in the foundation pit near the river was optimized and designed. Through theoretical calculations, reasonable distribution of dewatering wells at different distances from the river in the foundation pit was designed, and the dewatering effect of the foundation pit under traditional equidistant and design spacing arrangements was compared and analyzed through numerical simulations. The results indicate that optimizing the spacing arrangement can complete the precipitation task six days in advance, and the distribution of groundwater level in the foundation pit is relatively uniform after the precipitation is completed, achieving the optimization of the dewatering design of the riverside foundation pit and providing theoretical guidance for engineering practice.