Two-dimensional (2D) materials have attracted considerable research interest due to their potential optoelectronics applications. Black arsenic (B-As), a cousin of black phosphorus, has exceptionally high anisotropy in physical properties. In this study, we report the photonic spin Hall effect on the surface of two-dimensional B-As, manifesting in both transverse and in-plane beam shifts. By applying the beam propagation model near the surface of anisotropic 2D materials, we demonstrate that B-As exhibits higher or comparable photonic spin Hall shifts due to its extreme anisotropy. Moreover, a substantial spin-dependent beam displacement is observed when the incidence conditions meet the Brewster angle. These findings hold potential for novel scientific research and device applications involving anisotropic two-dimensional atomic crystals.