Based on MODIS-NDVI data, meteorological data, terrain data and human activity data, using trend analysis and other methods, the spatial-temporal change characteristics of vegetation cover in Chongqing from 2000 to 2019 were comprehensively analyzed by using geographic detector model. The influence degree and mechanism of each geographical factor and its interaction on vegetation cover in Chongqing were explored. The study finds that from 2000 to 2019:(1) The overall vegetation cover in Chongqing showed a fluctuating upward trend, with a growth rate of 4.4%/10A. The deviation value of NDVI first decreased and then increased. The change characteristics of vegetation cover were obvious and showed three stages. In the early stage, the average annual value of NDVI showed a downward trend; In the medium term, the average annual value of NDVI shows a slight growth trend; In the later stage, the average annual value of NDVI showed a rapid growth trend. (2) The vegetation cover in Chongqing is in the spatial distribution pattern of high in the East and low in the west. The high value areas are mainly distributed in the continuous area of Daba Mountains in Northeast Chongqing and the edge area of Wuling Mountain in Southeast Chongqing; Low value areas are mainly distributed in the fluctuating zone of the Three Gorges Reservoir area, Western Chongqing and the main urban areas. The spatial pattern of vegetation cover evolves from one-sided to diagonal in the east-west direction and from shallow U to deep U in the north-south direction, but the high-low concentration pattern of vegetation cover is basically stable. (3) The explanatory power of various geographical factors on the spatial differentiation of vegetation cover in Chongqing is as follows:annual average temperature (0.3459)>elevation (0.3281)>annual precipitation (0.2305)>human activity intensity index (0.1747)>slope (0.1008)>total radiation (0.0552)>slope direction (0.0034); the explanatory power of annual average temperature, slope direction and human activity intensity index generally increases, and the explanatory power of annual average precipitation, total radiation, elevation and slope generally decreases. (4) Each geographical factor interacted with vegetation cover change in Chongqing, and showed two types of double factor enhancement and nonlinear enhancement, but there was no interaction factor that interacted independently or weakened the explanatory power of vegetation cover change. The first dominant interactive factor of vegetation cover change in Chongqing is annual mean temperature and human activity intensity index, the second dominant interactive factor is elevation and human activity intensity index, and the third dominant interactive factor is annual mean temperature and total radiation.