Teachers' emotional leadership plays a crucial role in influencing college students' learning engagement. This study, grounded in Affective Events Theory, surveyed 1034 Chinese college students (649 females and 385 males) to examine their perceptions of teachers' emotional leadership, achievement emotions, emotional susceptibility, and learning engagement. The findings reveal that teachers' emotional leadership has a significant positive impact on college students' learning engagement. Specifically, college students' achievement emotions mediate the relationship between teachers' emotional leadership and their learning engagement. Additionally, college students' emotional susceptibility moderates the relationship between teachers' emotional leadership and their achievement emotions; however, it does not moderate the impact of teachers' emotional leadership on learning engagement through achievement emotions. This study validates the application of Affective Events Theory in the educational field, deepens the understanding of the mechanism and boundary conditions of emotional leadership's impact on learning engagement, and offers insights for enhancing college students' learning engagement.