In order to meet the needs of ecological barrier construction in the upper reaches of the Yangtze River, the Bailong River Basin with significant ecological and geological diversity as the research area was selected. Based on the sensitivity-resilience-pressure (SRP) conceptual model, an evaluation system comprising 14 indicators across four dimensions-geological structure, climatic environment, vegetation cover, and human activities was constructed. The eco-geological vulnerability index (EVI) was determined through a combination of analytic hierarchy process and entropy weight method. Through spatial autocorrelation analysis and geographical detector method, the spatial differentiation patterns and multi-factor driving mechanisms of eco-geological vulnerability in the basin were systematically investigated. The results demonstrate that the eco-geological vulnerability of the basin exhibits significant spatial agglomeration characteristics (Moran's I = 0.78, p<0.01). The vulnerability level is predominantly characterized by micro-vulnerability (68.56%), with extremely vulnerable areas (2.92%) concentrated in tectonically active steep terrain regions. Geodetector analysis reveals active fault density (q=0.832 5) and historical earthquake intensity (q=0.136 8) as key natural driving factors, while GDP density (q=0.049 4) and population density (q=0.051 1) constitute the primary sources of human-induced pressure. The interactive synergy between active fault density and historical earthquake intensity (q=0.919 9) significantly exacerbates regional vulnerability.This research indicates that eco-geological vulnerability results from the combined effects of natural geological background conditions and human activity disturbances. It is recommended to establish three-dimensional monitoring networks for high-vulnerability areas and implement differentiated ecological restoration strategies. The findings provide a scientific basis and decision-making reference for collaborative management of the geo-ecological system in the Bailong River Basin.