Abstract: Using high-power microwave to heat and melt the rock for rapid underground rock breaking is a brand-new drilling technology with potential technical advantages. Based on the 140 GHz high-power millimeter-wave system, the research on the rapid drilling technology of high-power millimeter-wave energy heating and penetrating rock is carried out. The dielectric loss characteristics of rock under microwave electromagnetic field is measured and analyzed. Using the multiphysics coupling method, the temperature distribution and ablation of rock under different beam sizes and incident powers are quantitatively simulated. It is found that the rock can be heated to more than 3000 ℃ immediately and undergo a phase change until evaporation when the peak power density reaches 1-2 kW/ cm². Furthermore, the analysis results indicate that the highpower and short-time microwave heating method is more efficient. This study will provide guidance for the exploration experiments on the 140 GHz high-power millimeter-wave experimental platform. The related application issues such as power loss of downhole long-distance millimeter-wave transmission are also discussed. And the possibilities of future high-power millimeterwave drilling applications are explored.