In this paper, the theoretical calculation and experimental research progress in mechanics and tribology of new two-dimensional layered black phosphorus materials were summarized. The future research and development of layered black phosphorus materials were also prospected. The focus was put on the negative Poisson‘s ratio and anisotropy of mechanical properties caused by the unique fold structure of black phosphorus. The effects of thickness, defect, pre-strain and environmental degradation on its mechanical properties were summarized. The research status of black phosphorus in tribology was summarized. The unique mechanical properties of black phosphorus materials were described from two aspects. Firstly, the negative Poisson‘s ratio characteristics of black phosphorus materials were confirmed through both theoretical calculation and experimental observation, which suggested the application of black phosphorus materials in fasteners, composite materials and national defense equipment. Secondly, the atomic structure with strong in-plane anisotropy of layered black phosphorus resulted in the anisotropy of mechanical properties, including the in-plane Young‘s modulus, tensile strength and critical strain. In advanced micro devices and integrated systems, crystal and mechanical anisotropy would promote applications in nanomechanical resonators, thermoelectric devices and motion sensors with adjustable functions that cannot be achieved with isotropic materials. In addition, the factors affecting the mechanical properties of black phosphorus were summarized, including thickness dependence of the structural properties of black phosphorus, the effects of different defects on its mechanical properties, the control of mechanical properties of black phosphorus by pre-strain, and the hindrance of environmental factors on the further development of black phosphorus devices. The research of black phosphorus in tribology was summarized from two aspects:microtribology and macrotribology. The microtribological studies of black phosphorus mainly focused on the anisotropy of tribological properties of black phosphorus, the effects of thickness and load on tribological properties, and the contribution of surface degradation to the lubrication. It was proved that the frictional anisotropy was caused by the coupling effect of the folded-structure of monolayer black phosphorus and the heterogeneous interaction between substrate and sample. The effect of layer numbers and applied load on its surface friction tests using AFM were summarized. The surface degradation of black phosphorus was considered as a major bottleneck for its application under environmental conditions; while its chemical activity could be made use of in tribology to achieve superlubricity. During the degradation of black phosphorus in ambient conditions, the strong interaction between few-layered black phosphorus and the water molecules favored the lower surface adhesion as well as lower interfacial shear stress between the layered black phosphorus and silicon dioxide wafer. The experimental research showed that the black phosphorus nanosheets, black phosphorus quantum dots and nanocomposites in oil-based lubricant as well as water-based lubricant could exhibit lower friction coefficient below 0.001 and better wear reduction property compared with other nanomaterial additives. The addition of black phosphorus nanoparticles to polymer matrix also enhanced the wear resistance of the produced composites. In particular, the excellent lubrication property of black phosphorus additives under extreme load of over 1.0 GPa was expected to promote the realization of superlubricity in the engineering field. At present, both the research area and application filed of black phosphorus are still expanding, and more basic problems need to be explored. However, the regulation of mechanical properties of black phosphorus and its application in different environment still meets great challenge. Compared with the performance of black phosphorus in liquid lubrication, the basic research and practical application of black phosphorus as a solid lubricant is still lack of systematic research, and its advantages in mechanical and tribological properties need to be fully utilized and developed.