Over the past decade, there has appeared a surge of research interest in language learners' academic engagement and psychological well-being as important factors in improving the quality of education. However, research on the roles of English as a foreign language (EFL) teachers' affective scaffolding in enhancing the academic engagement and psychological well-being of their students is relatively scant. Inspired by this gap, the current study aimed to investigate the impact of Chinese EFL teachers' affective scaffolding on their learners' academic engagement and psychological well-being. To this end, a total number of 1968 Chinese EFL learners participated in this questionnaire survey. The results of the study showed that EFL teachers' affective scaffolding positively and significantly predicted students' academic engagement and psychological well-being. More specifically, it was found that teachers' affective scaffolding explained about 73% and 65% of variances in EFL students' academic engagement and psychological well-being. Moreover, it was found that psychological well-being and academic engagement were positively correlated and predicted 56% of each other's variances. In accordance with these findings, educators are recommended to build up a harmonious teacher-student relationship to foster students' psych-emotional development.