The purpose of this study was to understand the relationship between principal's transformational leadership, teacher empowerment and teacher well-being, and to predict teachers' well-being by principal's transformational leadership and teacher empowerment. This study referred to the Multifactor Leadership Questionnaire compiled by Bass and Avolio, the adaptation of Spreitzer's Psychological Empowerment Scale, and the adaptation of Ryff and Keyes' Psychological Well-Being Scale, compiled into "Principal Transformational Leadership and Teacher Empowerment and Teacher Well-Being Questionnaire". The results of the study showed that there was a high correlation between the various variables, among which the correlation between teachers' work ability (empowerment) and personal growth (well-being) was the highest, showed that middle school teachers' empowerment and teachers' well-being were highly correlated, this study verified that principals' transformational leadership and teacher empowerment had predictive power for teachers' well-being. Finally, the conclusion of this research is that from the perspective of teachers, the principal should be a model for teachers and students in the school and pay attention to the principal's own job responsibilities. Teachers believe that empowerment depends on the teacher's own work ability, and maintaining positive interpersonal relationships can help get the best sense of well-being.