Most cancer patients have the personality characteristics of loneliness, silence and repression, and their interpersonal relationships mostly have the personality characteristics of submissiveness, non-aggressiveness, self-depreciation, cautiousness and conservatism, and often negative defense against frustration. These psychological factors can significantly inhibit the function of immune system, which reduces the function of self-recognition and phagocytosis of muscle immune cells, and cancer cells take the opportunity to occur and develop. In addition, mental stress not only weakens the immune function, but also tends to cause genetic program error exocytosis and increase the sensitivity of carcinogenic factors.