[目的] 识别兆河流域非点源污染分布特征及其关键源区，为流域污染控制和清洁小流域建设提供科学参考。[方法] 通过建立流域非点源污染控制模型，模拟研究该流域在现状年和规划年的非点源污染分布特征。采用单元负荷指数法识别流域的关键污染源区，预测不同非点源污染控制措施对流域污染负荷量的削减效果。[结果] 兆河流域规划年的氮磷负荷量比现状年分别增加45.3%和8.0%；县河、失曹河、裴河、盛桥河及环圩河子流域为流域非点源污染关键区；通过设置合理的工程措施和耕种管理措施可有效控制流域非点源污染。[结论] 合适的非点源管控措施有助于削减流域氮磷污染负荷量。耕种管理措施加工程措施为最佳管理措施，可以有效控制流域总氮和总磷的非点源污染。
[Objective] The distribution characteristics of non-point source pollution in the Zhaohe small watershed in different periods were studied in order to identify the key source areas in order to provide a reference for pollution control and clean small watershed construction.[Methods] The distribution characteristics of non-point source pollution of the basin in the current year and planning year were simulated by establishing a watershed non-point source pollution control model. At the same time, the load per unit area index method (LPUAI) was used to identify the key pollution sources in the basin, and the reduction effects of different non-point source pollution control measures on main pollutants were predicted.[Results] In the absence of non-point source pollution control measures, the nitrogen and phosphorus non-point source pollutants in the planning year of the basin increased by 45.3% and 8.0%, respectively, compared with the current year. Xianhe River, Shicao River, Peihe River, Shengqiao River, and Huanwei River sub-basins were the key areas of non-point source pollution in the basin. Non-point source pollution can be effectively controlled by setting reasonable engineering measures and farming management measures.[Conclusion] Appropriate non-point source control measures can help to reduce the nitrogen and phosphorus pollution load in the watershed. Cultivation management measures plus engineering measures are the best management measures, which can effectively control the non-point source pollution of total nitrogen and total phosphorus in the watershed.