Abstract: A proposal for the reutilization of abandoned mines has been mentioned, focusing on the development of an abandoned mine thermal energy storage system. This system ingeniously leverages the geothermal environment of deep mines to store surplus wind, solar, and industrial waste heat during the summer. The stored heat is then extracted in the winter for domestic heating, significantly reducing energy consumption and enhancing overall energy utilization. To evaluate the performance of this system, a three-dimensional THM (Thermo-Hydro-Mechanical) coupled numerical model was developed to simulate the heat transfer and temperature evolution over a ten-year period. The results indicate that the storage temperature of the abandoned mine thermal energy storage system decreases by less than 16 ℃, with the storage efficiency improving year by year. In the tenth year, the heating temperature increases by 3.8 ℃ compared to the first year, with the output temperature fluctuating only 2 to 3 ℃ throughout the entire winter heating period. After the abandoned mine thermal energy storage system stabilizes, the minimum output temperature remains stable at 71 to 73 ℃.Stress analysis reveals that the application of the thermal energy storage system does not compromise the stability of the mine roadway, ensuring the operational feasibility of the system. Sensitivity analysis, vis distance-based generalized sensitivity analysis method, further indicates that the injection temperature of the water flow has the most significant impact on the system's output temperature, followed by the roadway temperature and the injection rate. These findings provide valuable guidance for field tests and engineering applications of the abandoned mine thermal energy storage system, offering a promising approach for sustainable energy management and reuse of abandoned mines.