To explore the fractal distribution of surface soil particle size, organic carbon content of different particle size and the characteristics of carbon management index as well as their relationship in the desert steppe, 4 kinds of typical communities in Huamachi Town, Yanchi County, Ningxia Hui Autonomous Region, including Caragana korshinskii, Artemisia ordosica, Stipa breviflora and Agropyron mongolicum, were selected as the research objects. Using surface soil (0-5 cm) under typical vegetation canopy and intercropping habitats, the dynamic changes and their correlations of organic carbon content of different particle size and soil carbon pool in different vegetation surface soils were analyzed. The results showed that:(1) The distribution of soil particle size of the four kinds of typical communities showed a "single peak" shape, soil particle concentrated in the range of 2~250 μm, the fractal dimension D in the range of 2.56 to 2.63, the content of particle within 100~500 μm was the main reason for significant differences between vegetation types. (2) The organic carbon content under the canopy of four typical vegetation types was greater than that of intercropping habitats, the organic carbon content of thick sand >250 μm was the highest, the organic carbon content of different particle size components varied significantly between the shrub and herbage vegetation (p<0.05). (3) The soil TOC and AOC contents of the four typical vegetation types were all higher under canopy than those of intercropping habitats. TOC varied significantly among different communities. The carbon pool activity (A) and carbon pool management index (CPMI) under the canopy of shrub communities were relatively higher than those of intercropping habitats. Various indicators varied greatly among different communities due to different habitats, indicating that different typical vegetations played different roles in the carbon pool cycling mechanism, and enhanced soil carbon sink function with different degrees. (4) The relationship between soil particle size fractal and carbon pool stability was complex. Fine silt with 2~50 μm was an inorganic colloid of soil organic carbon. The increasing of its content significantly increased the opportunity for soil particles and organic carbon to form organic-inorganic cement, which was of great significance for maintaining soil structure and the stability of organic carbon pool. The research results indicated that appropriate vegetation restoration measures had certain reference value for maintaining the stability of soil particles and soil organic carbon pools in desert grassland.