With the increasing focus on the emotional nature of L2 writing instruction, chances have increased for L2 writing teachers to perform exquisite emotional labour in teaching writing knowledge and skills in the classroom, but our knowledge regarding the emotional labour strategies used by L2 writing teachers and their potential influence on their professional well-being is quite limited. To fill this void, this study used survey data on 301 university L2 writing teachers across various parts of the Chinese mainland to investigate the relationship between their emotional intelligence and professional well-being (i.e. teaching satisfaction, emotional exhaustion and personal accomplishment), with a particular focus on the specific mediating effect of various emotional labour strategies. Results showed that teachers' emotional intelligence was associated with their teaching satisfaction via a specific emotional labour strategy, the expression of naturally felt emotions, but not through the other strategies (i.e. surface acting and deep acting). Moreover, some specific dimensions of emotional intelligence, that is, others' emotional appraisal were related to L2 teachers' emotional exhaustion and personal accomplishment via surface acting. These findings highlighted the predictive effect of emotional intelligence and the mediating roles of emotional labour strategies in thriving L2 writing teachers' professional well-being. This study may allow L2 writing teachers and teacher educators to better understand their emotions and use specific emotional labour strategies to improve their teaching effectiveness and professional well-being.