With the development of Generative AI (GenAI) technologies such as ChatGPT, the landscape of teaching and learning in the educational field is undergoing profound transformations. This study focuses on how GenAI enhances teachers’ creativity in course designing and improve students’ learning outcomes. Based on the theory of generative learning, this study designed and conducted two experiments to explore the impact of GenAI on course design and its downstream effects on students’ learning outcomes. The study found that GenAI significantly enhances the novelty of course designs, regardless of the teachers’ levels of experience. Furthermore, course designs involving GenAI effectively improve students’ learning effectiveness through cognitive pathways rather than emotional pathways, further validating the potential applications of GenAI in the educational field. The results of this study provide important theoretical foundations for understanding the evolution of teachers’ roles in the GenAI era. Additionally, it offers practical guidance on how to leverage GenAI technology to enhance teachers’ creativity and improve students’ learning outcomes.