Understanding the dynamics of permafrost heavily relies on process-based simulations. In this study, we introduce a new model specifically designed for permafrost applications, the Flexible Permafrost Model (FPM). This model serves as an adaptable framework for implementing innovative permafrost-related physics. Long-term ensemble simulations indicate that the permafrost temperature increased at a rate of 0.11 °C dec^-1 since 1980 with a decreased area of ∼12.4 % over the Tibetan Plateau.