Abstract: To serve the national strategy of ecological protection and high-quality development in the Yellow River Basin and achieve refined management and control of the eco-geological environment, this study aims to reveal the spatial differentiation law of the eco-geological environmental quality (EGEQ) in Gansu section of the Yellow River Basin and quantify its key driving factors. Based on the theoretical framework of "geological stability-ecological sensitivity-resource pressure" (GEP), a three-dimensional multi-indicator coupling evaluation model (3D-MICE) containing 9 indicators was constructed. The analytic hierarchy process (AHP)-entropy weight method (EWM) combined weighting method was used to determine the indicator weights, and the geographic information system (GIS) spatial analysis technology was applied to complete the EGEQ evaluation at the 500m×500m grid scale. On the basis of comprehensive application of correlation analysis, geographical detectors and random forest (RF) models, the dominant driving factors and their interaction effects of the EGEQ spatial differentiation were revealed.①The EGEQ in the study area showed significant spatial heterogeneity, generally presenting a pattern of "high in the south and low in the north". Among them, the area of the high-quality area (Ⅰ) accounted for 15.35%, mainly distributed in the alpine meadow-wetland area of Gannan, and the area of the medium-and-below-quality areas (Ⅲ and Ⅳ) accounted for 65.12%, widely distributed in the loess hilly areas of Eastern and Western Gansu.②There was a significant positive correlation between the precipitation concentration degree (PCD) and the soil erosion modulus (SEM) (R²=0.83). For every 10% increase in PCD value, SEM value increased by an average of 15.2%.③The analysis of factor driving forces showed that the EGEQ spatial pattern was the result of the non-linear superposition of natural and human factors. Heavy precipitation was the key natural driving factor, while human activities such as mineral resource development and over-grazing, by destroying the stability of geological bodies and intensifying soil erosion, had a synergistic amplification effect with natural factors, jointly shaping the differentiation pattern of the regional eco-geological environmental quality.This study verifies the effectiveness and advancement of the 3D-MICE model in the evaluation of the eco-geological environment in complex mountainous areas. The generated high-precision evaluation results and zoning schemes could provide direct scientific basis and decision-making support for the "zoning management and control, precise policy implementation" of the territorial space ecological restoration project in Gansu section of the Yellow River Basin.