Abstract: Background The Western Sichuan region lies in the Hengduan Mountain tectonic zone in the eastern part of China's Qinghai-Tibet Plateau, at the junction of the Qinghai-Tibet Plateau and the Yangtze Block, two major tectonic units. It features a fragile ecological environment and complex geological structures. Under the dual impacts of climate change and regional economic development, ecological problems like vegetation destruction and soil erosion occur frequently, making it one of China's ecologically fragile areas. Methods Based on the relevant standards for ecological vulnerability assessment, this paper uses 3S technology and spatial analysis methods to process remote sensing data such as soil texture data and elevation data, and conducts an assessment and spatial analysis of the ecological vulnerability of Aba Tibetan and Qiang Autonomous Prefecture and Ganzi Tibetan Autonomous Prefecture in the western Sichuan region in 2023.Results The results showed that : 1) Overall, the Western Sichuan region is in an ecologically fragile area, accounting for 90.95% of its total area, with 8.94% in a generally fragile ecological environment and only 0.11% in an extremely fragile ecological environment. Among them, Shiqu County, Ruoergai County, Jiuzhaigou County, Wenchuan County, Luding County, Baiyu County, and Xinlong County have a relatively large proportion of areas classified as "generally fragile" and "fragile", and are generally in ecologically fragile areas. In contrast, small parts of Barkam City, Lixian County, Danba County, and Jiulong County are in extremely ecologically fragile areas, requiring strict protection and scientific restoration measures. 2)The protected areas in Western Sichuan are generally in ecologically fragile areas, accounting for 90.11% of their total area, with 9.70% in a generally fragile ecological environment and only 0.19% in an extremely fragile ecological environment. Among these, protected areas such as Changsha Gongma Nature Reserve, Ruoergai Wetland Nature Reserve, and Wolong Nature Reserve have a relatively large proportion of areas classified as "generally fragile" and "fragile", and are generally in ecologically fragile areas. Only very small parts of Taizhangou Nature Reserve, Maila Jiangcuo Nature Reserve, Genie Mountain Nature Reserve, and Huanglong Nature Reserve are in extremely ecologically fragile areas, which need special attention in ecological protection and management. Conclusions The entire Western Sichuan region and all its protected areas are situated in ecologically fragile zones. Both natural environmental factors and social-economic elements are the dominant factors influencing the distribution of ecological vulnerability levels in Western Sichuan, among which the impact of ecological environment changes on the ecological vulnerability of the Western Sichuan Plateau is becoming increasingly significant. The research results of this paper well reflect the current status of ecological vulnerability in various regions of Western Sichuan and it has certain scientific guiding significance for the formulation and implementation of ecological protection strategies in the Western Sichuan region.