Through case analysis and literature review, this study put forward the four-personality theory. As a new framework of personality structure, four people. The theory of case emphasizes that personality in the perspective of social situation consists of four dimensions: “Inner self ”, “Outer self ”, “Other self ” and“Non-self ”. The theory of personality reveals the influence of inner reality, external performance, expectation of others and cultural background on personality. This paper probes into the application of four-personality in psychological counseling cases, shows the influence mechanism of internal and external self-conflict on mental health, and advances some possible paths to alleviate psychological conflict through self-integration. In addition, the complex interaction between social structure and personality is discussed, and the key role of non-ego integration in promoting mental health is emphasized. The future research can explore the comparison between the four-ego personality theory and the traditional classical personality theory, further verify the clinical effect of the four-ego personality theory, and explore the influence of life experience stage and cultural background on the development of personality.