The sustained releasing heat of spent fuel has important impacts on the mechanical and seepage fields of the surrounding rock in high-level waste disposal repositories and its long-term stability. Generally

the thermal parameters of surrounding rock depend on the mineral composition

porosity and pore fluid of rock. To the multi-field coupling analysis of high-level radioactive waste geological repository

it is necessary to determine the values of thermal parameters accurately. Through the meso-mechanical analysis

the method was established to obtain the effective thermal parameters of the surrounding rock

including heat capacity

thermal conductivity coefficient

and thermal expansion coefficient. Based on Biot theory for porous media

a thermo- hydro-mechanical coupling model was built

and then its numerical simulation method of surrounding rock in the high-level radioactive waste repository was proposed. Finally

through the multi-field coupling software of COMSOL Multiphysics

the proposed numerical simulation method was verified using the in-situ test data of thermo-hydro-mechanical coupling in surrounding rock in the Mont Terri high-level waste underground laboratory in Switzerland. The simulation results agreed well with the experimental results. The evolution law of the thermo-hydro-mechanical coupling process was also discussed. The research results can provide a scientific basis for the safety assessment and site selection of high-level radioactive waste repository in China.