The research aims to address the issues including high groundwater level, severe salinization of cultivated soil adjacent to the Yellow River in the Yinbei Irrigation District. To investigate the spatio-temporal evolution laws of soil water-salt dynamics and groundwater depth in this area, a typical 43.33 hm² saline-alkali plot was selected in the drip irrigation-subsurface drainage salinization comprehensive management project area in Lingsha Township, Pingluo County. Monitoring stations for multiple indicators such as meteorology, soil moisture, salinity (electrical conductivity), and groundwater depth were set up to collect monitoring data regularly, while simultaneously machine learning models were utilized for data analysis. The results show as follows. In April before spring sowing, the surface soil (depth less than 0.2 m) is dominated by evaporation, and the characteristics of salt surface accumulation are obvious. During the summer irrigation period from June to August, the synergistic effect of irrigation and rainfall increased the moisture content in the middle layer (depth 0.4~0.8 m) to 26.76%~36.69%, intensifying the vertical migration of salt, resulting in the soil electrical conductivity that reaching peak values of 4.98 dS/m in June and July. The heavy rainfall in August reduced the groundwater depth to 0.86 m in September, with the coefficient of variation decreasing to 5.29%, and triggered a peak moisture content of 41.50% in the deep-layer soil (depth 1.0~1.2 m). During the non-irrigation period from September to October in autumn, under the dominance of evaporation, the surface moisture content decreased to 19.50%, while the accumulation effect of deep-layer soil salt became evident, with electrical conductivity reaching 5.08 dS/m. The subsurface drainage system effectively regulated the groundwater levels. It not only maintains groundwater depth within the range of 0.8~1.2 m during the flood seasons, but also facilitates the rapid discharge of precipitation that washes away soil salts due to heavy rainfall. During the dry seasons, as the backwater effect of Yellow River's diminishes and the strong evaporation prevails, the groundwater depth in the area is basically stabilized at around 1.5~1.8 m, which is significantly below the depth of the subsurface drains. This system can effectively suppress the rise of capillary water and the prevent salt reaccumulation in spring without the need for artificial intervention.