Abstract: Based on the observation data and meteorological data of winter wheat growth period from 1985 to 2022 at Shannan Agricultural Meteorological Observation Station in Xizang, this study expounded the impact of climate change on winter wheat growth period and its response mechanism. The results showed that during the growing season of winter wheat in Shannan, the temperature significantly increased, with a maximum temperature growth rate of 0.42 ℃/10 a, and the sunshine hours increased at a rate of 67.12 h/10 a, while the relative humidity showed a decreasing trend, with a decrease of 0.36%/10 a, especially from December of that year to March of the following year. The growth period of winter wheat shows phased changes, with an extended nutritional growth period (emergence-tillering) of 8.49 d/10 a, The nutritional reproductive growth period (tillering-heading) and reproductive growth period (heading-maturity) were shortened by 6.32 and 3.01 d/10 a, respectively. The meteorological factors during the critical growth period have a significant impact, such as a decrease in the lowest temperature during the wintering period (-0.11℃/10 a), which may increase the risk of frost damage. The significant increase in humidity during the grain filling period (20.67%/10 a) may affect grain quality and yield. The shortening of the entire reproductive period (0.84 d/10 a) and the advancement of the maturation period (5.92 d/10 a) may be related to the increase in temperature and optimization of photothermal resources.