As the basic unit of terrestrial ecosystems, the spatiotemporal evolution and carbon sink potential characteristics of soil and water conservation carbon pools in small watersheds have multidimensional features, which increases the difficulty of analysis. Therefore, this paper proposes an analysis of the evolution characteristics of soil and water conservation carbon pools and their carbon sink potential characteristics in small watersheds. The experimental results indicate that the carbon pool components for soil and water conservation accounting in small watersheds have a higher coverage, and the carbon pool components covered are more comprehensive. Time series analysis shows that under the application of soil and water measures such as terraced fields, artificial forests, and silt dams, the growth rate of vegetation carbon pool, soil carbon pool, and litter carbon pool is the fastest in the mid-term (5–15 years) of governance. Vegetation coverage, soil conditions, and hydrological conditions are positive factors affecting carbon sequestration. The growth rate and amount of carbon sequestration in soil and water conservation measures increased rapidly from March to April, revealing the evolution mechanism and driving law of carbon pools in small watersheds, which can provide scientific basis for strengthening ecological restoration.