Abstract: Classical strength theories represent a key yet challenging component of of mechanics of materials courses. In classroom instruction, teachers often focus on the elaboration of basic contents of strength theory, while overlooking its historical sources and logical thinking, which may lead to unsatisfactory teaching effects. Combining with engineering cases, the historical evolution process of the classical strength theories are traced in this paper, and the scientific research methods behind theories are explored. Furthermore, the core teaching ideas of the classical strength theories are summarized, which can help students to sort out the logical relationships in the establishment of the knowledge system. Practices show that the above teaching methods are beneficial to stimulating students' interest in learning and fostering their capacity for innovative thinking.