Macroscopic defects such as holes and the microstructure of mineral distribution in high-temperature underground engineering seriously affect the mechanical behavior of rock. In this study, the pre-holed granite model was established based on particle flow simulation, followed by heat treatment and uniaxial compression tests to analyse the effects of mineral and temperature on the macro-mechanical behaviour of pre-holed granite, revealing the evolution mechanism of crack and force chain field. The results indicate that the presence of hole has a significant deterioration effect on the mechanical properties of granite, but reduces the failure degree. The degradation effect of hole on the mechanical properties of specimen I-1 is significantly stronger than that of specimen I-2. The crack evolution of pre-holed granite under uniaxial compression mainly undergoes the initial stage, stable growth stage, rapid growth stage, and post-peak stage. The crack initiation position is mainly located in the area around the hole where the mineral bond strength is weak. Thermal stress leads to a decrease in the initiation stress of pre-holed granite and affects the initiation location and evolution process of cracks. Before the crack initiation, the compressive force concentration area is located on the left and right sides of the hole, and the tensile force concentration area is located on the upper and lower sides of the hole.