<p>This paper investigates the evolution of unfrozen water distribution in sandstone with varying pore sizes during freeze-thaw (F-T) cycles, taking into account moisture recharge. Firstly, a series of F-T treatments were conducted on sandstone under conditions of water recharge and non-recharge. The transverse relaxation time (T₂) spectra of pore water were obtained by conducting nuclear magnetic resonance (NMR) tests on thawed sandstone at various freeze-thaw (F-T) cycles, specifically at F-T numbers (1, 3, 5, 8, 12, 15, 20 and 30). Based on T₂ spectra of pore water, the distribution of three pore sizes (micropores, mesopores, and macropores) in sandstone was determined. Finally, T₂ spectra of unfrozen water were obtained by conducting NMR tests on low-temperature sandstone at various freeze-thaw (F-T) cycles. The distribution of three pore sizes in sandstone was analyzed to determine the percentage of unfrozen water present in each size category. Variations in the percentage of unfrozen water within three pore sizes in sandstone, as related to F-T numbers, were discussed. The results indicate that the distributions of unfrozen water in sandstone pores of three different sizes, characterized by F-T numbers, are significantly different. Under both water recharge and non-recharge conditions, the percentage of unfrozen water in micropores increases as F-T number rises, while the percentage in mesopores decreases, and the percentage in macropores remains nearly zero. At same F-T number, percentage of unfrozen water in micropore under water recharge is higher than that under water non-recharge conditions, and percentage of unfrozen water in mesopore under water recharge is lower than that under water non-recharge conditions.</p>