The freeze-thaw and chemical corrosion has a significant influence on the shear creep characteristics of jointed rock masses. To conduct a more realistic numerical simulation analysis of jointed rock mass engineering in cold regions, this study employed three-dimensional scanning and sculpting techniques to prepare joint surfaces with consistent morphologies in granite samples. Subsequently, shear creep tests were conducted on the jointed rock masses under freeze-thaw and chemical corrosion. Based on test results, the freeze-thaw and chemical corrosion damage variables were defined, a continuous yield joint model was introduced, and a shear creep damage model of jointed rock masses was established. The FISH language was used on the 3DEC platform to implement the secondary development of the model, and the rationality of the model was verified through degradation analysis and test data. Finally, the developed model was used to numerically calculate the creep characteristics of tunnel in cold regions, the research results show that: with freeze-thaw and chemical corrosion increases, the creep deformation and plastic zone of the tunnel gradually increase, and the maximum creep value consistently occurs near the tunnel vault. It is necessary to pay close attention to the deformation and stress of the tunnel vault, and take timely repair measures such as grouting reinforcement to prevent cracking of the local lining support structure. The research results provide an effective computational method for the stability analysis of rock mass engineering in cold regions.