Abstract: As a critical ecological barrier in the upper reaches of the Pearl River, Guizhou Province has distinctive mountainous topographic features and ecological environments, both of which play a vital role in sustaining the ecological security of the river basin. This study derived topographic factors from 12.5 m resolution DEM data, combined GF-6 high-resolution remote sensing images with the pixel dichotomy model to retrieve fractional vegetation cover (FVC), and systematically quantified the spatial coupling relationship between FVC and topographic factors in the Guizhou section of the Pearl River Basin. The results indicate that: (1) The terrain features showed remarkable spatial differentiation, with an overall terrain pattern of high northwest and low southeast. Slope gradient increased gradually from the central region to the periphery zones, and the dominant slope aspects were north, northwest, south, and southeast. Terrain relief exhibited a U-shaped spatial distribution pattern. (2) FVC displayed notable spatial heterogeneity, and high-FVC zones accounted for 45.66% of the total study area. The proportion of high-FVC areas exceeded 50% within the elevation zone of 2000–3000 m, which were mainly distributed on steep slopes (15°~<20°), abrupt slopes (20°~<25°) and areas with moderate terrain relief (300~900 m). (3) The explanatory power of topographic factors for FVC followed the order: slope (q=0.0342) > elevation (q=0.0071) > terrain relief (q=0.0058) >slope aspect (q=0.0014). All pairwise interactions between factors exhibited nonlinear enhancement effects.