Depression has become a topic of widespread concern around the world, and teachers' depression has also had an important impact on the healthy development of education. However, there are differences in the cognitive theory of depression and positive psychology about the mechanism of depression. This study attempts to verify the related viewpoints of the two viewpoints through empirical research. Three hundred and twenty eight preschool teachers were measured with authenticity scale, five facet mindfulness questionnaire, center for epidemiologic studies depression scale, and general alienation scale. Individual authenticity negatively predicted depression. Mindfulness can mediate the relationship between individual authenticity and depression. Self-alienation mediates the relationship between individual authenticity and depression. In addition, mindfulness and self-alienation played a sequential mediating role between individual authenticity and depression. Mindfulness and self-alienation play a sequential mediating role between individual authenticity and depression. This study not only confirms the relevant theoretical viewpoints of positive psychology on depression, but also believes that individual depression is not only affected by one's own negative bias but also by one's own positive factors. At the same time, the individual's own positive factors will affect the negative factors. This perspective will provide new literature references to existing relevant theories about depression. In addition, this study will also provide literature reference for early childhood education practice.