Under the paradigm of ‘New Liberal Arts’ construction, higher education is confronting the dual challenge of interdisciplinary integration and digital transformation. While Generative Artificial Intelligence (GenAI) offers vast potential for foreign language education, current applications often fail to foster deep learning, acting merely as answer providers rather than pedagogical guides. This paper proposes an innovative teaching model empowered by AI Educational Agents—intelligent systems designed with pedagogical logic to facilitate human-machine symbiosis. This research introduces a ‘Functionally Complementary’ agent role matrix, categorizing agents into Subject Experts, Functional Supporters, and Persona Immersions. Through a specific case study of the ‘IELTS Speaking Expansion Coach’ developed on the Doubao platform, this study demonstrates how AI agents can shift students from passive information reception to active critical thinking via scaffolded dialogue. The research argues that AI agents serve as the critical bridge between technology and humanities, reshaping the foreign language classroom into a personalized, interactive, and ethically grounded ecosystem. The findings suggest that when properly configured, AI agents can simultaneously improve teaching quality, expand access, and reduce costs, while maintaining the irreplaceable human elements of empathy, cultural transmission, and ethical guidance.