Example teaching theory was put forward by M. Wagenshein and Klafki in Germany. After World War II, under the slogan of "keeping pace with the development of modern science and technology", the education in West Germany continuously expanded the teaching content, which increased the burden on students and restricted their learning initiative. Example teaching theorists believe that in order to overcome the disadvantages of traditional teaching, we must reconstruct the teaching content, select the most typical materials in the subject materials, and form a knowledge-intensive area. In the dense area, the knowledge of all subjects converge and blend, and students form an overall cognitive structure by exploring and thinking about this dense area, so as to achieve the purpose of mastering other materials.