To reveal the spatial and temporal variation characteristics of soil water under different land use types in the southern tableland of the Loess Plateau, an automatic soil water observation system was used to monitor the soil water content (SWC) of 21 layers in 0-10 m profiles of alfalfa field, fallow field, fertilized cropland, and unfertilized cropland during 2014-2022. The spatial and temporal variation characteristics of the SWC and its influencing factors were explored. The results showed that the average SWC of alfalfa field was significantly lower than the other three land use types due to the strong water absorption effect of root system. With the increase of soil depth, the SWC of alfalfa field decreased first and then increased, while the SWC of the other three land use types showed an increasing trend. For the characteristics of seasonal variation, the seasonal dry-wet alternation soil layer of soil water were 0-2 m, 0-1 m, 0-3 m and 0-1 m, respectively, with the minimum and maximum data appearing in January to February and September to November, respectively. On an annual scale, SWC variability was the largest in alfalfa field, followed by that in fertilized cropland and in unfertilized cropland, while the fallow field was the smallest. In terms of long-term dynamics, the change of soil dry layer thickness was closely related to the interannual distribution of precipitation, the average annual soil water storage (SWS) of each land use types showed an increasing trend in the past 9 years, and the SWS increased significantly in the two water-abundant years of 2019 and 2021 in alfalfa field, where the recharge depth by precipitation infiltration could reach 4 m. Correlation analysis showed that land use, soil depth and clay content were the key factors influencing the SWC. The results can provide data for the observation and simulation of soil water in the deep soil profiles of the Loess Plateau.