In order to determine the variation characteristics of soil moisture after the transformation of karst slope land into the terraced field, the typical karst slope citrus orchard and terraced citrus orchard were taken as the research objects, and the soil water content of different depths soil layers (0-70 cm) was continuously monitored for one year (376 days). The results showed that: (1) The average soil water content of terraced citrus orchard (32.64%) was little different from that of sloping citrus orchard (33.05%). The soil water content (43.35%) in the surface layer (0-10 cm) of terraced orange orchard was significantly higher than that of sloping citrus orchard (34.24%). Both of them demonstrated a violent fluctuation in the rainy season and a relative gentle change in the dry season. In the terraced citrus orchard, there was a substantial difference in soil moisture between the surface soil and the lower layer, while there was no variation in the soil moisture among each soil layer in the sloping citrus orchard. (2) In the rainfall events with different rainfall amounts, the overall increase of soil water content in terraced citrus orchard was greater than that in sloping citrus orchard. Within 24 hours after the rain stopped, the decline rate of surface soil water content in the terraced orchard was slower than that in the sloping citrus orchard, but within a week, the water content of all soil layers in terraced orange orchard declined faster than that in sloping orange orchard. (3) The average relative available water of the terraced citrus orchard and sloping citrus orchard was 0.37 and 0.38, respectively. Compared with the non-karst region, the water conservation effect of terraced fields in karst peak-cluster depressions was relatively insignificant. The results of this study could provide a scientific basis for the quantitative evaluation of water conservation benefits of slope-to-terrace measure in karst area.