Despite previous research demonstrating the correlation between self-efficacy and SDL, these studies have overlooked the role of teachers and the mediating effect of cognitive reappraisal. To address this gap, this study collects data from 779 Chinese pre-service teachers (PSTs) at three time points--before, during, and after their teaching internship--to measure their levels of self-efficacy, SDL, and cognitive reappraisal. Cross-lagged analysis reveals that while cognitive reappraisal does not mediate the relationship between self-efficacy and SDL, SDL significantly predicts self-efficacy in the long term, and cognitive reappraisal and SDL positively influence each other. Unexpectedly, during the teaching internship, PSTs' self-efficacy does not significantly predict their SDL over time. This unexpected finding suggests that during the critical and formative phase of the teaching internship, factors such as practical teaching experiences and the challenges of real classroom environments may diminish the influence of self-efficacy on SDL. The results shed light on the relationships between self-efficacy, cognitive reappraisal, and SDL among PSTs. This study not only enhances our understanding of the psychological development of PSTs during their educational internships, but also provides theoretical support and practical guidance for improving the quality of teacher education.