[Objective] The ecological security of Western Sichuan Province was evaluated in order to provide a scientific basis for the ecological environment construction and socio-economic development planning of the region.[Methods] Based on GIS and remote sensing technology, an evaluation index system was constructed from two aspects of natural and human impacts, and the ecological security status of Western Sichuan Province in 2000, 2005, 2010, 2015 and 2018 was evaluated through fuzzy mathematical models, respectively.[Results] The ecological security in 40% of the region in Western Sichuan Province was in a dangerous state, showing a spatial distribution pattern of "high in the east and low in the west". The overall change trend of ecological security in Western Sichuan Province from 2000 to 2018 was "rising first, then decreasing slightly, and then rising". The Moran's I index of ecological security in Western Sichuan Province was around 0.5. The ecological security situation in the Western Baiyu, Batang, and Litang areas had been improved, while the ecological security in Eastern Jiulong, Yajiang, Muli, and Ruoergai areas was declined. Topography and vegetation were the main factors influencing ecological security in Western Sichuan Province.[Conclusion] The overall ecological security situation in Western Sichuan is relatively poor, but it shows a trend of improvement, with strong spatial aggregation. The management of the ecological environment of West Sichuan Province should consider its spatial differentiation characteristics.