Abstract:[Objective] In order to comprehensively understand the effectiveness of the construction of ecologically clean watersheds in the mountainous areas of northern Beijing, this paper quantitatively analyzes the functional structure of the watersheds and explores the influencing factors of each index on the development of the watersheds, in order to provide a theoretical basis for the comprehensive management and development of the watersheds in the mountainous areas of northern Beijing. [Method] In this study, in the management of ecologically clean watersheds in the northern mountainous areas established in 2021, four subsystems were established, including the Dianjiushi watershed in Yanqing District, the Yushuidong watershed in Huairou District, the Gubeikou watershed in Miyun District, and the Huluhe watershed in Changping District, and 13 representative evaluation indicators were selected based on the main characteristics and governance objectives of the study area. The comprehensive benefit evaluation index system of small watersheds in the mountainous areas of northern Beijing was constructed, and the system obstacle degree model was used to reveal the main influencing factors of the construction of ecologically clean small watersheds. [Results](1) The comprehensive management of each small watershed has achieved certain results. The Hulu River watershed has been upgraded from the primary standard to the intermediate standard, and the comprehensive construction of the Zhujiushi watershed, the Yushuidong watershed and the Gubeikou watershed has reached the primary standard. (2) The obstacle degree model is introduced to quantify the contribution of different influencing factors, which provides the accuracy of evaluation. (3) In the future development process of the small watershed in the mountainous area of northern Beijing, the ecological benefit should pay attention to the soil erosion modulus, the economic benefit should pay attention to the economic production ratio and land productivity, the social benefit should pay attention to the Engel coefficient and the proportion of rural employees, and the water quality improvement benefit should pay attention to the COD content. [Conclusion](1) The comprehensive benefit evaluation system of small watersheds proposed in this study is practical and feasible in the mountainous areas of northern Beijing. (2) Through the management of ecologically clean watersheds, the water environment and soil erosion in the mountainous areas of northern Beijing have been effectively controlled, the industrial structure in the watershed has been gradually improved, the ecological and human settlements have been improved, and the coordinated development of water and soil resources, ecological environment, and economy and society in the small watershed has been promoted.