According to different external forces, the tensile strength, compressive strength, and shear strength of the material. There is also a difference between yield strength and ultimate strength for steels with a yield point. Under the same conditions, if the strength of the material is high, the bearing capacity of the structural members is also high. The internal factors that affect the strength are: bonding, organization, structure, and atomic nature. For example, comparing the strength of metals with ceramics and polymer materials shows that the influence of bonding bonds is fundamental. From the perspective of organizational structure, there are four strengthening mechanisms that can affect the strength of metal materials, which are: (1) solid solution strengthening; (2) deformation strengthening; (3) precipitation strengthening and dispersion strengthening; (4) crystal Boundary and subcrystalline strengthening. Precipitation strengthening and fine-grain strengthening are commonly used methods to improve the yield strength of materials in industrial alloys. Among these strengthening mechanisms, the first three mechanisms increase the strength of the material while also reducing the plasticity. Only the refinement of grains and sub-crystals can increase the strength and plasticity. The external factors that affect the strength are: temperature, strain rate, and stress state. As the temperature decreases and the strain rate increases, the strength of the material increases, especially body-centered cubic metals are particularly sensitive to temperature and strain rate, which leads to low-temperature embrittlement of steel. The influence of the stress state is also important. Although strength is an essential index reflecting the intrinsic properties of materials, the strength values are different for different stress states. What we usually call the strength of a material generally refers to its strength when stretched in one direction.