This study investigates the effectiveness of a combined remediation technology for managing urban black and odorous water bodies. Based on the remediation concept of “treating external sources before internal ones, addressing tributaries before main streams, and prioritizing pollution control before ecological restoration,” and combining the causes of river odor with water quality analysis, a combined ecological remediation system was developed, consisting of “source control + non-point source management + internal source treatment + water network construction + ecological restoration.” This system was applied to the black and odorous rivers in the Xinfeng River basin of Daxing District, Beijing. Engineering practices indicate that after construction, the average concentrations of COD, NH3-N, and TP were reduced by 66.13%, 91.03%, and 88.97%, respectively, compared to 2016. The water quality at the outlet section reached Class IV surface water standards under both rainy and non-rainy conditions. This combined remediation system effectively eliminates the black and odorous conditions of river water, degrades river pollution, and provides good purification and aesthetic effects for river systems, serving as a valuable reference for similar projects.