In order to gain a deeper understanding of the effects of thermal cycling on the stress-strain behavior and crack development of granite under cyclic impact loading, a split Hopkinson pressure bar(SHPB) system was employed to conduct dynamic impact tests on granite specimens. Furthermore, a coupled SHPB model was constructed using the discrete element method(DEM), which effectively revealed the initiation, propagation, and coalescence of cracks, as well as the evolution of force chain damage. The results indicate that the sensitivity of granite's dynamic properties to temperature increases with rising impact gas pressure, although the temperature effect remains minimal under low impact loads. Under cyclic impact loading, the degradation rate of dynamic properties accelerates. However, a stable load-bearing stress threshold exists, and the peak strength attenuation is not significant, closely correlating with gas pressure. The coupled SHPB model accurately simulates the dynamic response of granite. High-temperature cooling treatment significantly alters the failure mode, predominantly characterized by tensile failure cracks, with crack development exhibiting a step-wise ascending pattern. The performance degradation caused by high temperature and cyclic impact is primarily attributed to the rupture and absence of internal particle contact force chains, identifying inter-particle interaction damage as the key factor. The research results provide theoretical support for the application of rock thermomechanical properties in geotechnical engineering.