Abstract: Accurately grasping the evolution trend of the ecological environment and effectively identifying its influencing factors are decisive for ecological environmental protection and the realization of sustainable development. This paper uses remote sensing technology to obtain the ecological factor indicators of the Three Gorges Reservoir from 2000 to 2020, constructs the Remote Sensing Ecological Index (RSEI), uses grid technology to map the administrative area of RSEI, and uses the geographic detector model to measure the impact of economic and social factors on the quality of the ecological environment. The results show that: (1) The overall ecological environment quality of the Three Gorges Reservoir area is showing a positive trend, and the areas with “medium” and “good” ecological environment quality levels account for an average of 72%. (2) The ecological environment of the Hubei section of the Three Gorges Reservoir area is better than that of the Chongqing section. The ecological environment of Xingshan County in Hubei is the best, with an average RSEI index of 0.474. The areas with poor ecological environment are concentrated in the core urban area of Chongqing. (3)Population density, urbanization, and the three major industries have a significant impact on the ecological environment, and per capita GDP can be linked with other factors to have a strong influence. Studies have shown that to improve the ecological environment of the Three Gorges Reservoir area, it is necessary to further improve the economic level, pay attention to the transformation of the secondary industry, and focus on controlling the population size and urbanization development.