为深入理解热循环对花岗岩在循环冲击下的应力-应变行为及裂隙发展的影响，采用分离式霍普金森压杆（split Hopkinson pressure bar, SHPB）系统对花岗岩样品进行动态冲击试验，并结合离散元法（discrete element method, DEM）构建SHPB耦合模型，模型有效揭示了裂隙萌生、发展和贯通，以及力链损伤的演化。结果表明：花岗岩动态特性对温度的敏感度随冲击气压增加而增强，但在低冲击荷载下温度影响较小；循环冲击荷载下，动态特性劣化速度加快，但存在稳定的承载应力阈值，峰值强度衰减不显著，且与气压密切相关；SHPB耦合模型能准确模拟花岗岩动态响应；高温-冷却处理显著改变破坏模式，以张拉破坏裂纹为主，裂隙发展呈阶梯状上升；高温和循环冲击导致的性能劣化，主要是由于内部颗粒接触力链断裂和缺失，指出颗粒间相互作用损伤是关键因素。研究成果为岩土工程中岩石热力学性质的应用提供了理论支持。

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.