The changing characteristics of the frozen ground (FG) are essential indicators of climate change. The soil temperature (ST) on the Tibetan Plateau (TP) during 1987- 2018 was simulated using the coupled model of RegCM4.7-CLM4.5. The results show that there is a significant warming trend in the ST on the TP, and the warming trend is higher in October-May (0.040 ℃∙decade⁻¹) than in June-September (0.026 ℃∙decade⁻¹), with the maximum value in February (0.058 ℃∙decade⁻¹). Spatially, the warming is most significant in the Three River Source Region (0.15~0.20 ℃∙decade⁻¹) and near the Himalayas and Kunlun Mountains (0.20~25 ℃∙decade⁻¹), with the warming trend greater in winter and spring than in summer and autumn. Air temperature (AT), total precipitation (TPR), maximum snow depth (MSD), and maximum frozen ground depth (MFD) can significantly affect the ST variation. The AT (R=0.851) and TPR (R=0.411) can accelerate the soil warming, while the MSD (R=-0.381) and the MFD (R=-0.770) can decelerate the soil warming. The AT has a strong influence on the ST in all four seasons, while the effect of the TPR is strongest in autumn (R=0.836). The retarding effects of the MSD and the MFD are strongest in summer (R=-0.772 and -0.35 respectively). Both the observation data and numerical simulation analyses indicate that the FG on the TP shows a degradation trend, and the consequent hydrological, ecological, and climatic effects deserve sufficient attention.