<p>Hot Dry Rock (HDR) geothermal resources have garnered significant interest because of their vast development potential. The low porosity and permeability characteristic of HDR geothermal reservoirs require stimulation for effective exploitation. Hydraulic fracturing is a conventional stimulation method. However, hydraulic fracturing often entails elevated injection pressure and rate, which has the potential to increase the risk of induced seismicity. This study proposes cyclic thermal stimulation as a pretreatment method for hydraulic fracturing based on laboratory experiments. In this study, the granite samples underwent 0–10 heating and cooling stimulation cycles at varying temperatures of 150, 200, and 250&#xa0;°C. Subsequent uniaxial compression and flow-through tests were conducted to evaluate the changes in permeability and mechanical strength with increasing thermal stimulation cycles and loading temperatures. The results demonstrated that cyclic thermal stimulation aggravates the damage to granite, leading to increased permeability and decreased mechanical strength. Importantly, the most significant increase in permeability occurred during the first few cycles, after which a threshold was reached where further cycles had little impact on permeability. Elevated stimulation temperature resulted in more significant increases in permeability and decreases in mechanical strength, and more cycles were needed to reach the permeability threshold. Laboratory results confirmed that cyclic thermal stimulation is a viable pretreatment method. It could lower fracturing pressure and seismic risks during hydraulic fracturing, providing a safer and more effective way to develop Enhanced Geothermal System (EGS).</p>