▎ 摘　　要

Based on photonic topological transition (PTT), the dynamically tunable angular optical transparency of graphene-based hyperbolic metamaterials is theoretically and numerically investigated in mid-infrared region. The results indicate that an ultra-narrow angular optical transparency window with angular full width at half maximum of 0.8 degrees appears near the transition point of PTT for TM waves, which is achieved by tailoring the metamaterial's equi-frequency surface from closed ellipsoid to open hyperboloid. In addition, we further propose the application of TM-pass/TE-reflect polarization beam splitter in the case of normal incidence. Besides, the broadband of angular optical transparency can be realized by changing the Fermi level of graphene.