The evolution of granite's mechanical characteristics with temperature is a contentious topic in the field of rock mechanics, and little research has been done on how its microstructures vary with temperature. The design of the constant amplitude temperature cycle and peak increasing temperature cycle loads was based on modern testing technology and experimental apparatus, with a particular emphasis on the generation and propagation law of granite microcracks under their action and a discussion of the influence of weathering degree. The results suggest that the peak temperature has a stronger influence on the formation of the fracture network than the total number of cycles. Temperature load can be slightly mitigated by weathering, but a thermal cycle with an increasing peak value can promote the growth of surface fracture. The understanding of the evolution of rock mechanical properties under temperature will be promoted in this study.