Abstract: Soil thickness is closely related to the development degree of rocky desertification, and soil is the basis of ecological restoration and agricultural production in karst rocky desertification areas. In order to examine the spatial distribution law of soil thickness in typical plateau rocky desertification areas, by combining field investigation of soil thickness with geostatistic methods, this paper analyzes the spatial distribution characteristics of soil thickness and its influencing factors in the karst plateau gorge area of the Zhenfeng-Guanling Huajiang small watershed in Guizhou. The results show that the average soil thickness in the study area is only 26 cm, and the average thickness of soil is: Slope farmland > wasteland > forest land. The spatial variability of soil thickness in the study area is mainly intensity. The spatial distribution continuity of soil thickness in wasteland is better than that of forest land and slope farmland. The spatial distribution of soil thickness in forest land has obvious mutation. The soil thickness in slope farmland is characterized by point distribution, and the soil thickness near crops is large. There are significant negative correlations between soil thickness and altitude, bedrock exposure rate and slope. Serious soil erosion under natural and man-made effect is the main reason for the uneven distribution of soil thickness in the study area, and the combination of engineering measures and biological measures can be used to control rocky desertification in the study area. The results are of guiding significance for the control of rocky desertification in the study area and control of soil erosion, ecological restoration and rational agricultural production in other similar areas.