<p>Granite has been selected as the host rock for deep geological repositories for high-level radioactive waste (HLW) in China due to its low permeability, excellent mechanical integrity, and strong radionuclide adsorption capacity. Nevertheless, potential leakage of waste could lead to the migration of radionuclides through groundwater along fractures in the granite (including both natural fractures and those induced during repository construction and operation). This radionuclide transport process represents a critical and challenging issue in the safety assessment of HLW disposal. Single-fracture column transport experiments have become a critical method for studying the transport behavior of radionuclides. In this study, the sorption and desorption behaviors of uranium (U-238) in a single fractured granite of Beishan, Gansu Province, China were simulated under the influence of various different common groundwater ions to explore the impact of environmental factors on uranium transport properties. The experiments were conducted using rock columns made from Beishan granite and exposed to different single-salt background solutions, including NaCl, Na₂SO₄, NaHCO₃, NaF, and CaCl₂. The results indicate that different ions have significant effects on uranium transport: Ca²⁺ and SO₄^2−&#xa0;ions promote uranium transport at an acidic condition, while F⁻ ions increases uranium retention within the granite. The underlying mechanism by which ions influence uranium transport involves the formation of complexes between the ions and UO₂²⁺ at specific pH values which alter the sorption behavior of uranium on granite surfaces. Key transport parameters were derived by fitting the breakthrough curves, shedding light on the transport characteristics and influencing factors of uranium transport through granite fractures. These findings provide essential experimental data for the safety assessment in HLWs disposal. Furthermore, we propose a significant strategy for investigating uranium transport under multi-field coupling conditions. Future studies will focus on exploring the transport characteristics of uranium in fractured systems under real-world multi-field coupling conditions and using transport parameters for modeling.</p>