[Purpose] Check-dams are used to directly intercept sediment and control soil erosion, significantly changing the lateral migration process of soil organic carbon (SOC). The spatial distribution of SOC in the dam and the impact of watershed land use on SOC distribution in the dam are explored, which can provide scientific basis for the coordinated development of check-dam construction and watershed ecological environment. [Method] This article focuses on three small watersheds with significant differences in the proportion of grassland, sloping farmland, and terraced land use types in the Chabagou catchment. A combination of remote sensing interpretation, field sampling, and indoor testing was used to study the spatial distribution characteristics of soil organic carbon (SOC) in dams and their response to land use. [Result] (1) In the vertical direction, SOC content is highest in the surface soil (0-20cm) and rapidly decreases with increasing soil depth. The variation of SOC content in the deep layer is relatively small, fluctuating around 3.5 g/kg; (2) In the downstream direction, due to the influence of soil erosion and sedimentation characteristics, the content of SOC is relatively high in the middle and later stages of the dams; In the direction parallel to the dam, the content on both sides is relatively high. (3) The B check-dam with a high proportion of terraced fields in the watershed has a significantly higher mean SOC (0.44 g/kg) than the A check-dam (0.39 g/kg) and C check-dam (0.35 g/kg). (4) The SOC of terraced fields in the watershed is the highest, and the construction of terraced fields affects the soil particle size of eroded sediment, resulting in a significant positive correlation between the proportion of terraced fields in the watershed and the SOC of the soil layer on the dam surface. The surface SOC carbon content of the grassland is relatively low, resulting in a negative correlation between the surface SOC content of the dams and the grassland. The SOC density of sloping farmland is positively correlated with the SOC content on the surface of the dams, but due to the small area of sloping farmland, its proportion is not significantly correlated with the SOC content on the surface of the dams. [Conclusion] Due to soil erosion, SOC sources, and mineralization characteristics, the soil SOC in the surface layer of the dam is the highest, which rapidly decreases and tends to stabilize with increasing soil depth. The high level of SOC and the erosion characteristics of finer particles in terraced land may lead to the highest SOC content in the B check-dam site, which has the highest proportion. This article reveals the spatial distribution characteristics of SOC in dam controlled small watersheds in semi-arid areas, and also explores the positive effect of terrace construction in the watershed on SOC in the surface soil layer (0-200cm) of the dam land.