Land use and vegetation cover are direct manifestations of human activities in transforming nature. In order to quantitatively assess the impact of human activities on soil erosion, this study focuses on Changting County, a typical red soil erosion-prone area in southern China. Using remote sensing images from 11 years between 1988 and 2020 with 3- or 4-years interval, the USLE model was applied to evaluate the spatiotemporal characteristics of soil erosion in the county over the past 30 years, and the quantitative impact of different land use and Fractional Vegetation Cover (FVC) changes on soil erosion was analyzed. The results showed that:(1) The severe soil erosion in Changting County is mainly concentrated in the central areas of the county, including Hetian Town, Sanzhou Township, and Cewu Township. Over the past 30 years, the intensity of soil erosion showed an increasing trend followed by a decreasing trend. From 1988 to 1994, the situation of soil erosion became increasingly severe, with a soil erosion rate as high as 30.49% in 1994. Since the mid-1990s, the situation gradually improved, and by 2020, the soil erosion rate had decreased to 6.22%. (2) During the two periods of 1988-1994 and 1994-2001, the area of forest land converted to bare land was the largest, resulting in an average increase in soil erosion of about 93% for each period. During the two periods of 2001-2010 and 2010-2020, the area of bare land converted to forest land was the largest, resulting in an average reduction in soil erosion of about 73% for each period. (3) For over 30 years, the FVC in Changting County has shown a decreasing trend followed by an increasing trend. The average FVC decreased from 44% to 35% between 1988 and 1994, after which it began to increase. As of 2020, the FVC has increased to 79%. The soil erosion amount was inversely proportional to the FVC, and the impact of FVC reduction on soil erosion was greater. On average, for every 1% decrease in FVC, the soil erosion increased by 74 900 tons, while for every 1% increase in FVC, the soil erosion decreased by 37 500 tons. (4) The FVC in Changting County was negatively correlated with soil erosion intensity, and the sensitivity to soil erosion was positively correlated with slope. Under low slope conditions, soil erosion changed more uniformly with FVC, but under high slope conditions, when FVC was less than 60%, the sensitivity to soil erosion was high. For each 10% increase in FVC, the average soil erosion modulus in areas with a slope greater than 15° was reduced by 262.73 t/(km²·a). This study helps to analyze the spatiotemporal changes of soil erosion in Changting County over a long time series and the impact of human activities on soil erosion, providing important scientific support for future land use planning and ecological protection in Changting County.