Unlike traditional macro-power theories, Foucault's micro-power theory reveals the complex inter-constructive relationship between linguistic norms and social power structures. His assertion that "discourse is power" provides a crucial perspective for analyzing the mechanisms of power operation within linguistic practices[3]. This study employs Foucault's power theory as its analytical framework. Through an in-depth interpretation of the movie My Fair Lady, it uncovers the inherent paradox between linguistic norms and subject empowerment, thereby transcending conventional boundaries in film analysis. This approach not only offers a novel theoretical pathway for interpreting My Fair Lady but also deepens the practical significance of Foucault's power theory within cultural criticism, exposing the concealed power dynamics within linguistic practices and their dialectical shaping of subject freedom.