Considering the important influence of freeze-thaw processes on land-air interactions， this paper couples an improved freeze-thaw parameterization scheme into the BCC_CSM2_MR model and conducts a one-year simulation experiment， dividing the simulation period into four stages： beginning of freezing， complete freezing， beginning of ablation and complete ablation according to the annual change of soil layer， and analyzing the soil temperature， soil temperature， near-surface wind field on the plateau and the meteorological elements of soil temperature， soil temperature， near-surface wind field and precipitation were analyzed.The results show that the new freeze-thaw scheme has good improvements for both shallow and deep soil temperatures， especially in the central part of the plateau.The improvement of the optimized freeze-thaw parameterization scheme for soil moisture is significant， and the root mean square error and bias of the new scheme are significantly reduced across the Tibetan Plateau in all four freeze-thaw periods， mainly in the central part of the plateau.The wind speed deviation in the northern and central parts of the plateau is reduced during the freezing and thawing phases， which is closer to the comparison data.The correlation coefficients have been improved.The results of the study show that the improved soil freeze-thaw parameterization scheme has a corresponding improvement over the original scheme in the BCC_CSM， and has a positive impact on the simulation of the climate and major circulation systems in China.