<p> Background: The experimental study of rock dynamic failure has always been the focus of scholars. However, the existing experimental techniques are difficult to monitor the deformation of the failure area during the rock failure process. Objective: The paper aims to propose a novel experimental and analytical approach for rock dynamic deformation measurement and failure mechanism, demonstrating its feasibility as a proof-of-concept study. Methods: The presented measurement method uses a Hopkinson pressure bar to perform dynamic experiments on fractured rock. A novel measurement system, incorporating a high-speed camera and a self-developed digital image–corner correlation method, addresses image distortion caused by differences in the object distance of corner points on the surface of cylindrical rock samples by applying surface normalization. Results: The results from this proof-of-concept study illustrate the dynamic evolution of cracks and the strain field on the observed surface during the fracture process of rock under impact loading. A crack evolution factor and strain concentration factor based on strain statistics are introduced. Finite element simulations model the entire fracture process in sandstone under SHPB dynamic compression, tracking stages from crack initiation to penetration. Conclusions: The presented method captures the evolution of surface and internal deformation during the dynamic failure of fractured sandstone. It provides model-based interpretations of the failure process in fractured sandstone and offers preliminary insights into its macroscopic mechanical behavior.</p>