With the flourishing of positive psychology, there is a heightened emphasis on the value and significance of engagement. Although recent years have witnessed the growing interest in learner engagement with feedback in L2 writing, little attention has been towards understanding the role of teachers in fostering their students' engagement. To fill this gap, our exploratory study examined the effects of teacher scaffolding on EFL learners' engagement with teacher written feedback. Anchored in a high school in mainland China, our study employed a mixed-methods design, collecting data from multiple sources (i.e., questionnaires, semi-structured interviews, teacher written feedback, and first as well as revised writing samples) over a semester. The findings revealed that the teacher adhered to the key tenets of positive psychology and implemented positive pedagogical practices to facilitate students’ revision. Both quantitative and qualitative data showed that with teacher scaffolding Chinese high school EFL learners actively engaged with teacher written feedback from affective, behavioral, and cognitive perspectives. Our study concludes with the important pedagogical implications.