Graphene and black phosphorus have attracted tremendous attention in optics due to their support of localized plasmon resonance. In this paper, a structure consisted of graphene–black phosphorus heterostructure is proposed to realize terahertz anisotropic near-perfect absorption. We demonstrate that strong plasmonic resonances in graphene–black phosphorus heterostructure nanoribbons can both be provided along armchair and zigzag directions, and dominated by the distance between the graphene and black phosphorus ribbons. In particular, the maximum absorption of 99.6% at 10.2 THz along armchair direction can be reached. The proposed high performance anisotropic structure may have promising potential applications in photodetectors, biosensors, and terahertz imaging.