The magneto-optical effect has demonstrated increasing scientific significance and technological potential in the study of magnetic materials. However, due to the complexity of its theoretical framework, it is often difficult to cover in depth within standard courses such as optics, electromagnetism, and computational physics. As a result, students frequently encounter challenges such as unclear physical intuition and complicated mathematical derivations. Starting from the Fresnel equations, this paper systematically constructs a complete theoretical framework linking magnetic circular dichroism in materials to the expressions of Kerr and Faraday rotation angles. By integrating typical application scenarios such as magnetic domain imaging and optical isolators, the abstract theory is organically connected to practical cases, providing undergraduate students with a teaching reference that combines theoretical depth and practical relevance for a deeper understanding of magneto-optical effects.