Abstract: Beijing City has a dense population and limited regional water resources.Unreasonable development and utilization of water resources once led to groundwater overexploitation, water environment pollution and other problems.How to evaluate and promote the sustainability of water resources utilization is a basis to alleviating the water resources problems in Beijing City.Therefore, in order to analyze the current situation of water resources utilization in Beijing City, this paper establishes an evaluation index system according to the social-economic-ecological environment composite system, determines the index weight by using the knowledge granularity and attribute importance method, then quantitatively evaluates the sustainability of water resources utilization in Beijing City from 2004 to 2020 based on the set pair analysis and attribute identification method.Based on the results, we compare the evaluation results under different weights and analyze the impact of available water resources on the sustainability.The results show that the weight determination method based on knowledge granularity and attribute importance is feasible in the evaluation of water resources sustainable utilization in Beijing City.In addition, the overall level of sustainable water use is getting better and better year by year.Although the results obtained by different evaluation methods are slightly different, the overall trend is basically the same.The amount of available water resources is an important factor affecting the sustainability of water resources utilization in Beijing City, and the Middle Route of South-to-North Water Diversion Project provides favorable conditions for ensuring the amount of available water resources in Beijing City.This study has certain reference values for the formulation of policies and plans related to water resources protection and exploration in Beijing City in the future.