Ecological water conveyance (EWC), as an important anthropogenic regulation measure for restoring degraded river ecosystems in arid regions, exerts profound impacts on regional water-salt balance and soil environmental processes by altering surface water-groundwater interactions. The middle reaches of the Kongque River, located on the northeastern margin of the Tarim Basin, represent a typical inland arid zone where intensive agricultural activities intersect with fragile ecosystems, characterised by frequent surface water-groundwater interactions, pronounced groundwater depth fluctuations, and complex soil water-salt dynamics. In this study, soil samples (0-200 cm) were collected from 30 profiles across 5 representative sections before and after EWC to measure soil water content (SWC), salinity, and texture. Using remote sensing data, statistical analysis, and interpretable machine learning models, we systematically investigated the spatial distribution, temporal changes, and controlling factors of soil water content and salinity in the middle reaches of the Kongque River. The results showed that (1) the D (single fractal dimension of soil) values of the surface-layer soils in the study area generally ranged from 1.6-2.6, and no clear pattern in soil texture was observed with increasing distance from the river. (2) SWC and soil salinity in the surface layer exhibited moderate spatial variability, with salinity exhibiting higher variability than SWC. Following EWC, the spatial variability of SWC and soil salinity increased and decreased, respectively. (3) Overall, the SWC within 0-1 km of the river channel increased after EWC; however, soil salinity also increased, indicating that salinisation in the surface soil was not alleviated. (4) Before EWC, SWC in the middle reaches of the Kongque River was primarily controlled by soil texture, soil depth, and elevation (topography), with contribution rates of 40.2%, 16.8%, and 11.1%, respectively. Soil salinity was mainly influenced by soil depth, land-use type, and groundwater depth (33.8%, 21.5%, and 13.8%). After EWC, SWC was predominantly governed by soil texture, soil depth, and elevation (topography) (55.3%, 16.8%, and 8.8%), while soil salinity was mainly affected by soil depth, land-use type, and elevation (28.2%, 26.4%, and 14.0%). The direct effect of EWC and time effects on soil water-salt dynamics are relatively limited. The results indicate pronounced land-use differences in the soil water-salt response to EWC, suggesting that targeted regulation should integrate artificial leaching, coordinated irrigation, and process-based monitoring. This study elucidates the key mechanisms governing soil water-salt responses to EWC in arid inland river basins and provides a scientific basis for riparian ecological water management and ecosystem restoration.