Investigating micro-structural changes in red sandstone under varying temperature and cooling modes provides a scientific basis for optimizing construction engineering performance and preserving ancient red sandstone structures. In this study, we investigate red sandstone microstructure using XRD and SEM after treatment with various temperatures and cooling methods. The results demonstrate that elevated temperatures induce physicochemical reactions in feldspar minerals, increasing relative quartz content, while cooling methods show limited effects on mineral composition. Additionally, higher temperatures cause fissure expansion, with water cooling accelerating structural degradation.