Abstract: Bending deformation is an important chapter in material mechanics, and it is also one of the difficulties in the knowledge of material mechanics that students generally reflect. In order to deepen students' understanding and mastery of the neutral layer, Hooke’s law, stress distribution and other knowledge points, we have carried out an extended teaching of bending normal stress in material mechanics. On the basis of the teaching of planar bending single beam, the bending normal stress of superimposed beams and bonded beams is explained, and the normal stress test experiments of superimposed beams and bonded beams are carried out. Furthermore, we have added the virtual simulation of bending normal stress, and used finite element software to carry out simulation calculations for the above two types of beam structures, and used virtual simulation to concretize physical concepts such as stress distribution and neutral layer that cannot be intuitively demonstrated by traditional teaching. Through the systematic teaching of theory, simulation and experiment, students can establish a more in-depth intuitive impression and knowledge concept of the definition of bending stress, neutral layer, Hooke’s law, etc.