<p>With the advancement of educational reform, teachers’ mental health has been receiving increasing attention. Based on Kumpfer’s resilience framework, the present study explored how social support (external factor) impacted depression among teachers and further examined the mediating role of resilience (internal factor), as well as the moderating effect of years of teaching experience (internal factor). Using convenience sampling, 608 teachers from Guangxi Province participated in the survey. The questionnaire consisted of items about personal characteristics, the Symptom Checklist-90, the Resilience Scale for Adults, and the Social Support Rating Scale. To test the constructed model, structural equation modeling was conducted to test the mediating effect, while multi-group comparisons were conducted to test the moderating effect of teaching experience. The results revealed that social support negatively predicted depression, with resilience playing a partially mediating role in this relationship. Furthermore, significant differences were observed in the mediation models across teacher groups: the path from resilience to depression was stronger among teachers with over 10 years of teaching experience. In conclusion, these findings suggest that social support is beneficial to teachers’ mental health and the psychological mechanisms were different across different teacher groups, indicating that it is necessary to provide sufficient social support and targeted interventions to improve teachers’ well-being.</p>