Abstract: The excavation of hard rock tunnel is a difficult problem. In this paper, the microwave heating model of basalt is established by using the finite element software to analyze the effect of the ambient temperature, heat transfer coefficient, irradiation time and heating path on the microwave irradiated rock. Results show that both reducing the ambient environment and increasing the heat transfer coefficient can lower the surface temperature of the rock sharply and form a large temperature gradient in the rock, thus producing the temperature stress and causing the rock failure. Prolonging the microwave irradiation time can increase the temperature stress, but the damage effect is not proportional to the irradiation time. In the case of the constant total time, the microwave irradiation effect can be significantly improved by changing the microwave heating path and adding a natural cooling process in the middle of heating.