This paper aims to explore the concept of psychological harmony from the perspective of positive psychology as well as the relationship among the psychological harmony and mental health, self-consistency and congruence, and subjective well-being. Psychological harmony is a kind of unified and relatively stable relationship which among the psychological elements and all the elements that directly influences it in the overall sense of harmonization. Psychological harmony included four subsystems, internal mental harmony, mental harmony between individuals and matters, interpersonal mental harmony and body-mind harmony. There was no original relationship between the psychological harmony and the positive psychology in terms of the background and the research context. But its connotation in essence belongs to the category of positive psychology. Psychological harmony exists in the linkages among two or more psychological elements and focus on horizontal relationships between them. But mental health focus on the overall functional status or characteristics emerged from the interaction of all the psychological elements. The connection between psychological harmony and mental health is that both of them require the coordination among all kinds of psychological elements. Mental health including psychological harmony and the psychological harmony is the important content of the mental health and the reflection of it. The differences between the psychological harmony and self-consistency and congruence are that they are subordinate to different disciplines. The connotations are also different between them either. The means of “mind” in the psychological harmony contains one′s cognition, emotion, willing and personality. But it is just confines in the scope of personality in self-consistency and congruence. The connection between psychological harmony and self-consistency and congruence is that the latter is a vital parts the former or even the basis of it. The differences between the psychological harmony and subject well-being is that psychological harmony is focus on the unified and relatively stable relationship which among the psychological elements and all the elements that directly influence it in the overall sense of harmonization. But subjective well-being describing or reflecting a kind of emotional state which is based on cognition. Compared with the subjective well-being, the subjectivity of psychological harmony is weaker. The connection between psychological harmony and subjective well-being is that both of them reflecting the positive aspects of one′s mind. And the two variables can predict index of each other. And above all, it is the creativity of this paper to fit the concept of psychological harmony into the field of positive psychology as well as reveal the differences and connections with mental health, self-consistency and congruence, and subjective well-being.