<p>Using a sample of 912 vocational college teachers in China, this study empirically examines the impact of emotional labor, such as surface acting, expression of naturally felt emotion, and deep acting, on the mental health of Chinese vocational college teachers. Robustness tests were conducted by replacing explanatory variables and research methods to explore the mediating effect of vocational identity on the relationship between emotional labor and mental health among Chinese vocational college teachers, as well as the moderating role of teacher-student relationships in this relationship. Research findings indicate that surface acting exhibits a significant positive correlation with mental health issues among vocational school teachers, while expression of naturally felt emotion and deep acting demonstrate a significant negative correlation. Heterogeneity analysis reveals that surface acting positively impacts the mental health of female teachers, those aged 35 and above, teachers with over 10 years of teaching experience, and high-income vocational school teachers. Conversely, natural acting and deep acting exert a positive influence on the mental health of male teachers, those aged 35 and above, teachers with over 10 years of experience, and low-income teachers. Mediation analysis indicates that occupational identity exerts a significant mediating effect on the relationship between emotional labor and the mental health of vocational school teachers. Moderation analysis reveals that teacher-student relationships exert a significant inhibitory effect on the relationship between surface acting, expression of naturally felt emotion, and deep acting and the mental health issues of vocational school teachers. These findings provide robust evidence and important practical implications for effectively alleviating mental health challenges among vocational college faculty.</p>