It is commonly found that the white material CaSO₄2H₂O appears on the surfaces of archaeological sites in Shaanxi Province within a short time after excavation. In our research, soil columns were used to simulate the process of CaSO₄2H₂O surface deposition. The results show that the site formed a new interface layer after excavation, and groundwater migrated upward as a result of evaporation at the surface, simultaneously bringing soluble salts in the soil to the surface, gradually increasing concentration until reaching the peak values. The contents of Ca²⁺ and SO2-₄ ions in the surface soil were dozens of times higher than those in the original soil after the experiment, which indicated that the CaSO₄2H₂O on the surface of the site was the result of water and salt transport. This research could provide evidence for the prevention of CaSO₄2H₂O generation after site excavation.