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Accurately evaluating the influence of temperature variations is crucial for geothermal engineering. Existing conventional testing methods are limited in providing detailed characterizations of reservoir micro properties at high temperatures. This study employed variable-temperature AFM testing techniques to examine sandstone and limestone under in-situ temperatures (25-200°C). The study analyzed the mechanisms behind the temperature effects on rock properties and established theoretical models for porosity and permeability variations with elevated temperatures based on these mechanisms. The research revealed that sandstone and limestone exhibit similar temperature effects at high temperatures. The pore fractal dimension of sandstone and limestone does not change with temperature change. As the temperature increases, sandstone and limestone experience mean roughness (R_a) and porosity …