Snow cover and frozen soil on the Qinghai-Xizang Plateau （QXP） play an important role in the global water cycle.In this paper， the Regional Climate Model （RegCM4） coupled with the Community Land Model （CLM4.5） was utilized to conduct regional simulation experiments on the QXP.This was done to explore the mechanism of snow influence on soil water and heat transfer during freezing-thawing periods.Our results showed that RegCM4-CLM4.5 can effectively simulate the characteristics of high and low snowfall years on the QXP， and the center of simulated snow depth was 10~20 cm higher than remote sensing snow depth.The simulation effect of soil temperature was better than that of soil moisture.The correlation coefficient R of simulated soil temperature was 0.95~0.98， and the correlation coefficient R of simulated soil moisture was 0.68~0.89.Comparison of the simulated soil temperature and moisture content of high and low snowfall years on the QXP revealed that the abnormal amount of snowfall had heat preservation and humidification effect on soil.During freezing period， the soil temperature in high snowfall year is higher than that in low snowfall year.During melting period， the soil moisture content in high snowfall year is higher than that in low snowfall year.The frozen soil would also hinder the infiltration of snow melt water， so the difference of soil moisture between the high and low snowfall years was not more than ± 2%.In permafrost area， when there was more snowfall， the freezing depth increased， which was conducive to the development of frozen soil.And in seasonal permafrost area， the increase of snowfall was not conducive to the development of frozen soil.