Teacher wellbeing is a multifaceted concept involving complex dimensions concerning a teacher’s professional, psychosocial, and efficacious state in the workplace, and holds strong implications for teacher retention, instructional effectiveness, and student learning. To date, few models studies model risk factors influencing teacher wellbeing using a facet-level approach. This study leverages an original field survey, which was designed based on the internationally validated Teaching and Learning International Survey (TALIS) item inventory and analyzes 5252 primary and secondary school teachers’ response data in a large metropolitan in Western China. This study integrates Self-determination theory (SDT) with Seemingly Unrelated Regression (SUR) to identify factors linked to teacher wellbeing traits, including competence, autonomy, and relatedness. Findings reveal that teacher pay satisfaction, workload, career motivation, career expectations, self-efficacy, teacher-student relationship, and teacher-administrative relationship factors jointly predict wellbeing, but their saliency is highly heterogeneous across wellbeing facets. Implication from the perspective of school governance on how to adjust school management strategies based on teachers’ psychological needs to improve teachers’ wellbeing. The results show that in western China, the key to teacher empowerment at the school governance level is to make teachers feel supported rather than redundant administrative affairs through the decentralization of school management power, so that teachers can improve their sense of accomplishment and sense of belonging at work through participating in school management and strength their educational responsibility and belief, thereby promoting work engagement and wellbeing. Strategies are identified to enhance teacher wellbeing in Western China by fostering supportive school climates, reducing work stress, and maintaining professional relationships, thereby benefiting both teachers and students.