Exploring the transition of vegetation cover in mountain areas and comprehensively assessing the impacts of various drivers on them are important ways to understand ecosystem processes such as global climate change and the carbon cycle. The Three Gorges Reservoir Area is an important protected area for the ecological environment of the Yangtze River Basin and provides a variety of ecosystem services. Based on Normalized Difference Vegetation Index (NDVI) data, this paper proposes the theory of vegetation cover transition in the mountainous areas, and uses geographical detectors to analyze the relative contribution of potential factors to vegetation cover in the hinterland of the Three Gorges Reservoir Area from 1999 to 2020. The results show that:(1) In the past 30 years, the vegetation cover in the hinterland of the Three Gorges Reservoir Area indicated a benign development trend as a whole, with a growth rate of 0.006/a and a spatial characteristic of "low from east to west and high from north to south; low in the middle, high on all sides"; (2) The spatial evolution of vegetation cover at different times presents "overall improvement and local degradation". The spatial transformation is summarized into four modes:stable, fluctuating, degraded and restored, while the stable distribution is the mainstay. The three stages of reduction, transition and recovery have been experienced in time; (3) Vegetation cover is mainly driven by soil type 0.225> landform 0.200> land use degree 0.181> altitude 0.158> lithology 0.152, and the role of man-made and climatic factors is weak, indicating that the natural factors are the dominant factors affecting vegetation cover. In addition, the interaction of the two factors is more important in influencing vegetation cover than each factor acting alone. These findings are conducive to better understanding the complex mechanisms of vegetation change in the mountainous areas and provide a reference for the management and conservation of vegetation in fragile ecosystems.