This course starts from the stress and deformation of mechanical components, and then describes the concepts of tension, compression and shear, torsion, bending internal force, bending stress, bending deformation, stress and strain analysis, strength theory, combined deformation, compression bar stability, and related calculation and analysis methods. Finally, on this basis, this course will describe the more in-depth content of materials mechanics such as dynamic load, alternating stress, energy method, statically indeterminate structure, etc.