Objective This study aims to investigate the spatiotemporal evolution characteristics and driving factors of soil conservation in the Three Gorges Reservoir area. Methods Taking Wanzhou， a representative county in the Three Gorges Reservoir area， as a case study， multi-source remote sensing data from 1990 to 2020 were used. The InVEST model was applied to assess the spatial differentiation characteristics of soil conservation function， and the Geodetector model was employed to analyze the driving mechanisms of its evolution. The influence of slope on soil conservation in sloping cropland and corresponding regulation measures were also explored. Results 1） From 1990 to 2020， soil conservation function in Wanzhou exhibited a trend of increase followed by decrease， with a spatial pattern of higher values in the east and lower values in the west. Land use types were mainly sloping cropland and forest land. 2） Soil conservation function in Wanzhou demonstrated significant spatial clustering characteristics， with low-low clustering areas expanding from the north to the southwest， and high-high clustering areas concentrated in the eastern region. Kernel density high-value areas were consistently located in the central region， and kernel density values showed a fluctuating decrease followed by an increase. 3） Natural environmental factors were the primary drivers of spatial differentiation in soil conservation function. Slope （q=0.71） was the dominant factor， followed by vegetation coverage （q=0.43） and soil type （q=0.24）. Interactions among all factors showed enhancement effects， among which combinations such as slope and temperature， and slope and vegetation coverage， exhibited the strongest effects （q>0.75）. 4） Soil conservation function in sloping cropland was closely related to slope. On slopes from 3° to 8°， soil conservation function remained stable ［from 120.64 t/（hm²·a） to 379.35 t/（hm²·a）］. On slopes from 8° to 25°， it was at a moderate level ［from 61.17 t/（hm²·a） to 81.93 t/（hm²·a）］. Differentiated management measures could be adopted for different slope gradients： low-slope areas should adopt straw mulching and contour ridge tillage， medium-slope areas should combine engineering and vegetation measures， and slopes >25° should prioritize conversion of cropland to forest and grassland. Conclusion The results provide a scientific basis for soil erosion control and ecological restoration in the Three Gorges Reservoir area.