Aeolian sandy soils are an important carbon sink for dissolved inorganic carbon (DIC), however, the underlying mechanisms are still mystery. To solve this issue, the adsorption of HCO3- and CO32- on aeolian sandy soil particles was studied using molecular dynamics simulation and adsorption experiments. Both HCO3- and CO32- can be adsorbed, albeit with varying adsorption capacity, distributions, and local environment, which was influenced by the pH value and concentration. The adsorption mechanisms of DIC were though hydrogen bonds or cation bridges, as well as in the form of single or multiple molecular clusters, which were regulated by the pH level. At pH=7.5, HCO3- was mainly captured by hydrogen bond and in a form of single molecule; at pH=9.5 and 11, both HCO3- and CO32- were mainly adsorbed as DIC clusters through the linkage of Na+ bridge. The HCO3- cluster mainly found at pH=9.5, comprising of HCO3--Na+-CO32- complex, whereas the CO32- cluster mainly observed at pH=11, comprising of CO32--Na+-CO32-. The CO32- cluster exhibited greater stability compared to the HCO3- cluster. These results are valuable in enhancing our understanding of the carbon cycle process and carbon balance dynamics in arid and semi-arid regions.