The mechanical behaviors of shale exhibiting transversely isotropic characteristics under dynamic loading hold immense significance for addressing structural instability in geotechnical engineering. To unravel the impact of transverse isotropy on the deformability and tensile strength of shale subjected to dynamic loads, a series of impact Brazilian tests were conducted on shale specimens using the split Hopkinson pressure bar (SHPB) testing system. High-speed digital image correlation technology was utilized to monitor the fracture propagation process meticulously. The experimental results reveal a notable anisotropy in failure strength, with variations observed based on the bedding angle of the embedded layers. Specifically, shales with vertical beddings typically exhibit higher tensile strengths compared to those with parallel beddings. The predominant failure mode observed is the interplay between tensile and/or shear fractures. As the loading rate increases, layer-activated fractures become more prevalent. Furthermore, four distinctive failure patterns of transversely isotropic shales, characterized by different mechanisms, were identified under dynamic Brazilian testing. The deformation and fracture response of shales under dynamic loading were found to be highly sensitive to the strain rate. Consequently, a novel strength criterion was proposed, incorporating the strain rate effect, based on the Brazilian splitting data and a dynamic coordinate system. This criterion not only accurately represents the dynamic strength behavior but also offers fresh insights into the influence of the strain rate on strength. It has proven its effectiveness in predicting the dynamic strength characteristics of shale.