Introduction Some students in current society do not pursue careers related to their majors after graduation, which may be the result of low professional commitment of college students, and the teaching enthusiasm of college teachers presented in the classroom may influence students’ professional commitment. This study considered the effect of teacher enthusiasm on students’ emotional state of boredom during class and its effect on students’ engagement in learning. This correlational study aims to explore the relationship between perceived teacher enthusiasm and professional commitment as mediated by class-related boredom and learning engagement. Methods This study is a correlational design and adopts regression analysis. The respondents were college students (n=358; 68% female, 22% male) of different grades and majors from universities in Wenzhou, China. Questionnaires about perceived teacher enthusiasm, professional commitment, class-related boredom and learning engagement were adopted to measure the study variables. Results The results reveal that although there is no significant direct influence between perceived teacher enthusiasm and professional commitment, perceived teacher enthusiasm affects students’ professional commitment through students’ class-related boredom and learning engagement, and there is an indirect and statistically significant correlation between them. Conclusion This study provides insight into the facilitative effect of teachers’ increased enthusiasm on students’ professional commitment and how this facilitative effect is triggered through the mediating role of class related boredom and learning engagement. Future research should explore the theoretical and teaching significance and how to guide and enhance students’ professional commitment.