In China, burnout is common among kindergarten, primary, and secondary school teachers. Previous studies have demonstrated that professional identity positively affects the prevention of burnout among teachers. However, studies on the mediating mechanisms behind and the moderating factors affecting this relationship remain scarce. In this study, the mediating role of work engagement as well as the moderating roles of self-efficacy and perceived organizational support in these relationships was examined. A total of 3,147 kindergarten, primary, and secondary school teachers completed self-reported questionnaires. SPSS 21.0 was used to conduct data analyses, and ordinary least square (OLS) regression was used to conduct mediation and moderation analyses. Results found that the relationship between teacher professional identity and burnout was partially mediated by work engagement. Through work engagement, teacher professional identity had the biggest predictive effects on burnout when the scores for self-efficacy and perceived organizational support were high. Implications for preventing burnout among teachers in the future were provided.