Sichuan Province is extremely rich in water resources, but it has prominent problems such as uneven spatial distribution, seasonal and engineering water shortage. In order to provide scientific support for the rational allocation of water resources, it is urgent to evaluate the current situation and trends of water resources carrying capacity (WRCC). An evaluation index system is constructed from three aspects: water resources, socio-economics and ecological environment. Principal component analysis method is used to analyze the spatio-temporal changes and the key driving factors of WRCC in Sichuan Province from 2012 to 2021. The grey prediction GM (1,1) model is used to predict the change trend of WRCC from 2022 to 2026. The results showed that: (1) From 2012 to 2021, the WRCC of Sichuan Province follows a fluctuating ascending trend, with significant spatial differences. There are larger disparities between the eastern and western regions. The WRCC of Ganzi Prefecture and Aba Prefecture in the western plateau region is the highest, while the WRCC of northeast and southern Sichuan fluctuates and increases in the central region. (2) Forest coverage, annual per capita GDP, proportion of tertiary industry added value in GDP and population density are the main indicators affecting WRCC at the provincial scale, while total water consumption, per capita water resources and population density are the main factors affecting WRCC at the city-state scale. (3) The WRCC is expected to increase year by year at the provincial scale from 2022 to 2026. At the city-state scale, all cities are expected to exhibit an increasing or stable trend except Bazhong, Guangyuan, Nanchong and Liangshan prefecture.