<p>Rock engineering is susceptible to damage by cyclic dynamic loading such as explosions. The damage evolution and permeability of rock are closely related to its microscopic dynamic behaviour, which is not well understood. In this study, a multiscale research method combining the split Hopkinson pressure bar (SHPB) system and computed tomography (CT) technique is used to analyse the dynamic behaviour, fractured feature block prefailure, internal three-dimensional microcrack propagation, permeability, and influence of the evolution of microfractures on the dynamic features of limestone. On the basis of the above objectives, dynamic experiments were conducted using the SHPB system to clarify the dynamic features, cumulative dissipated energy (CDE), and cracking evolution of limestone subjected to cyclic dynamic loading. The CT technique is used to inspect the microscopic structural and permeability evolution of the limestone sample during the loading process. The results illustrate that a greater impact loading leads to a greater CDE and growth rate. Moreover, spiral microcracks and noninterpenetrated small cracks also appear in the limestone sample with a relatively high impact loading. Additionally, the fracture rate can help elucidate the damage and permeability variation features of limestone samples. The increase in the mean surface fracture rate with increasing impact loading reveals more severe damage and high permeability in the limestone sample. The volumetric fracture rate and permeability exhibit a nearly linear growth tendency with increasing CDE. The results of this study can assist decision-makers in evaluating the safety of rock structures and guiding design and disaster prevention in rock engineering.</p>