<p>This study evaluates the effects of microwave, chemical, or blasting treatment on hot dry rock (HDR) with various lithologies and initial temperatures. HDR samples, including three granites and one sandstone, were subjected to microwave irradiation, chemical dissolution, or blasting after being heated to target temperatures (25–500&#xa0;℃). Scanning electron microscopy (SEM), nuclear magnetic resonance (NMR), and tensile tests were employed to analyze microstructural damage, porosity, and tensile strength changes. The experimental results show that: (1) Microwave treatment achieved the highest heating rates in G1-type granite, followed by G2, G3, and S-type sandstone, attributed to the varying content of strong and moderate microwave absorbers in the lithologies. (2) Chemical treatment revealed that S-type sandstone exhibited the highest dissolution rate due to its higher content of soluble minerals, while G1-type granite had the lowest due to a higher proportion of insoluble minerals; higher initial temperatures accelerated dissolution for all lithologies. (3) Blasting treatment demonstrated peak hoop stress differences correlated with lithological wave impedance, with G1-type granite showing the highest peak hoop stress and S-type sandstone the lowest, leading to more severe damage in higher impedance lithologies. (4) Tensile strength decreased across all lithologies after treatment, with microwave treatment causing the most significant reduction in G1-type granite, chemical treatment resulting in the greatest reduction in S-type sandstone, and blasting causing significant reductions across all lithologies. (5) Higher initial temperatures exacerbated damage for all treatment methods, increasing porosity growth rates and tensile strength weakening consistently across lithologies. These findings provide critical insights into pre-damage mechanisms for optimizing enhanced geothermal systems (EGS) and advancing HDR resource development under complex geologic conditions.</p>