The black phosphorus (BP) crystals and two-dimensional black phosphorus (2D BP) are prepared from amorphous red phosphorus by mechanical ball milling- liquid exfoliation method. The spectrophotometric analysis shows that a few layers of 2D BP have been successfully prepared. Aiming at the characteristics of 2D BP that was easily degraded in the natural environment, a low-cost solvothermal method was used, and 2D BP and nickel chloride are used as raw materials to prepare a green and pollution-free transition metal phosphide (TMPs) heterojunction was prepared. Metal ions are preferentially deposited on the defects of 2D BP such as edges and unsaturated sites, forming a 2D BP / P-rich TMPs in-plane heterojunction (BP / NiP3). It occupies the defects of BP nanosheet to enhance its stability.