Introduction Water scarcity severely constrains the sustainability of plantations in semi-arid regions by reducing soil water availability and increasing drought stress. Thinning is a crucial silvicultural practice for forest restoration and water regulation, yet the responses of soil water content (SWC) to varying thinning intensities during a dry year and a normal year remain insufficiently understood.Methods This study evaluated the effects of thinning on SWC in Chinese pine (Pinus tabuliformis) plantations on the Loess Plateau of China, with five thinning intensities: 0% (control), 15% (light), 30% (moderate), 45% (heavy), and 60% (extremely heavy). SWC at depths of 0 -200 cm was repeatedly monitored during the growing seasons of 2023 (dry year) and 2024 (normal year). Vegetation structure, rainfall redistribution, and soil properties were periodically measured.Results Thinning increased mean 0 -200 cm profile SWC by 4.96 -18.06% in the dry year (2023) and by 5.33 -18.87% in the normal year (2024), compared with the 0% thinning control. Although SWC in 2024 was higher than in 2023, thinning exerted a similar effect on SWC in both study years, with the 30% thinning intensity yielding the most pronounced positive improvement in deep SWC (30 -200 cm; +19.14% -25.26%). Thinning significantly improved the temporal stability of deep SWC in 2024, and the 15% and 30% thinning treatments consistently exhibited relatively low coefficient of variation values during the monitored observation period. Redundancy analysis (RDA) indicated that SWC was positively associated with net precipitation in both soil layers and in both study years. Additionally, deep SWC exhibited a positive association with soil organic carbon during both years, as well as with fine-root traits in 2024.Discussion Based on the above results and the regional soil water carrying capacity, we recommend prioritizing an initial thinning intensity of approximately 30% (approximate to 2,000 stems ha-1) to alleviate soil desiccation in Chinese pine plantations. This finding informs adaptive eco-rehabilitation strategies for plantation restoration on the Loess Plateau and other semi-arid regions and provides a practical basis for improving soil-water regulation and plantation resilience under increasing climatic stress.