Abstract: For a better understanding of the water movement regulation of soil in Karst areas, this paper took the soil of the desertification area in Guizhou as research subject, analgzed the critical saturated water, water leakage rate and water evapotranspiration rate with the method of simulated precipitation. The results indicated that it reached saturation field capacity when precipitation simulation was 130~140 mm, which was the leakage critical point; while it reached the maximum infiltration rate within 10 min when the precipitation simulation was 145~165 mm; while it reached the maximum in the first 5 minutes when the precipitation exceeded 165 mm and water loss was in the way of evaporation when precipitation was less than the critical point. This study figures out the fundamental rule of soil water movement in Karst desertification area and provides the relevant basic data for future research with the significance of ecosystem protection in Karst area.