Abstract: The analysis of bending normal stress and deformation of homogeneous beams under pure bending is a core topic in Mechanics of Materials. Leveraging the comprehensive reform of the solid mechanics curriculum, this paper extends the teaching of homogeneous beams to the bending analysis of heterogeneous composite beams. By applying the equivalent section transformation principle, a rectangular double-layer composite beam is transformed into a T-section homogeneous beam, establishing an explicit relationship between the equivalent moment of inertia and the mid-span deflection. On this basis, a "relative method" is introduced to clarify the experimental principle for determining the equivalent elastic modulus of functionally graded coatings via three-point bending tests, highlighting its advantages over the "direct method." The teaching implementation features an autonomous experimental module where students design and conduct tests to measure the coating's modulus. Additionally, a numerical simulation module guides students through virtual experiments to verify the feasibility of the theoretical model and the experimental scheme. This integrated approach helps students understand the comprehensive application of theory, experiment, and simulation in engineering, deepening their mastery of key concepts such as equivalent transformation, moment of inertia, deflection, and three-point bending.