Abstract: In order to scientifically evaluate the river sustainability and identify its main restrictive factors, 22 indicators were selected from 6 aspects: water security, water resources, water ecology, water environment, water economy and water culture, so as to construct an evaluation index system and model for river sustainability evaluation.Through weighting and identifying the main characterization factors by AHP method, introducing Fuzzy mathematics and Rank-sum ratio(RSR)method to improve TOPSIS model, weput forward the evaluation method of sustainability level.Taking Shaanxi section of Weihe River from 2010 to 2019 as an example, this paper analyzed the change of river sustainability level with time, and explored the sensitivity of river sustainability to index change in different periods with sensitivity index SI.The results showed that:(1) The main characterization factors of the sustainability of Weihe River in Shaanxi Province were runoff storage capacity and aquatic organism integrity index;(2) The overall sustainability level of the Shaanxi section of Weihe River had an upward trend year by year, and the grade has increased from preliminary sustainability(2010)to relatively sustainability(2019);(3) The main sensitive factors of sustainability in the Shaanxi section of Weihe River were different in different years, and the overall sensitivity to the fluctuation of flood control standard compliance rate I2 and eutrophication index I11 were relatively large.The research results verified the rationality of the evaluation method of river sustainability index which can provide reference for the sustainable development of river basins and water resources management.