Straw return modifies topsoil properties that are crucial for understanding soil-atmosphere interactions and their impact on soil hydrothermal conditions in seasonally frozen areas. However, the effects of uniformly returning crushed straw (3-5 cm in length at 1.6-1.8 kg & sdot;m-2) on the surface energy balance (SEB) and soil water-heat dynamics during the freeze-thaw period remain inadequately quantified. We conducted a two-year field experiment in a cold-arid region of Northwest China, employing a Bowen ratio energy balance system (BREBS) to monitor SEB components (Rn, Gs, H, LE), alongside soil temperature and moisture. Results demonstrated that straw return (ST) obviously altered SEB components during freeze-thaw periods. Specifically, over the two-year period, seasonal variations showed that ST reduced Rn by 8.6-9.1 W & sdot;m-2 relative to NT, decreased Gs by 0.24 W & sdot;m-2, lowered LE by 49 %, while increased the Bowen ratio by 48 % and H. During the thawing period, diurnal variations showed LE decreasing by 36 % and H increasing by 11 % under ST compared to NT. Furthermore, ST delayed topsoil thawing by 3-7 days, increased unfrozen water content (UWC) by 2.9-4.3 %, reduced freezing depth, and stabilized deep-layer soil temperature and moisture. These findings endorse straw return as a viable strategy for conserving soil moisture, mitigating frost damage, and optimizing spring sowing schedules in arid cold regions.'