Modern medical psychological research confirms that a person’s personality type has an important impact on his or her mental and physical health. That is, people with certain personality traits tend to be prone to certain mental disorders or physical illnesses. The most typical is that people with type A personality traits (strong sense of time urgency, competitive and hostile) have 3 times higher risk of coronary heart disease than those with type B personality (opposite to type A). Therefore, people with type A personality behavior should be reminded to consciously change, adjust or control the characteristics of their personality that are not conducive to physical and mental health in order to reduce or avoid the occurrence of coronary heart disease. Likewise, people with type C personality traits should be reminded. C is the first letter of Cancer, which indicates that people with this personality trait are prone to cancer. Cancer is one of the three major diseases that endanger human health and life, and its cause is still unclear and there is no special treatment. Many studies at home and abroad believe that there is a correlation between the occurrence of cancer and human personality. That is, people with positive, optimistic and open-minded personalities, who can resolve bad emotions in time, will have slow growth of cancer tumors, or even recede naturally; while people with type C personality will accelerate the development of cancer tumors. People with C-type personality are often overly anxious about life, career and interpersonal communication, not good at socializing with others, experiencing deep inner experience of misfortunes and being overly patient, thus being in a state of long-term repression, not even daring to face conflicts and being depressed. It is inevitable that the immune function will decline, thus leading to various metabolic dysfunctions and inducing all kinds of cancer, therefore, C-type personality is also called cancer personality. Psychologist Spinoza believes that mental activity and physical activity of the body are equivalent and are two aspects of the same process. The characteristic of mental activity of type C personality reflects that the bad mind does not get reasonable and sensible catharsis, and due to closure and repression, the physiological activity of the body will also be negative, which leads to cancer. Psychology is a function of the brain, which is a reflection of objective reality, and the brain’s activity directly affects the physiological activity. The psychology of negative type C personality people directly induces negative physiological activities. The air pollution and social environment are the same, but why some people suffer from cancer while others do not, more than 60% of the factors are psychological factors, and it is the C-type personality that plays a role. Usually it is difficult to distinguish between B and C personalities. It is actually very simple: for example, if you kick a type B personality, he will not only not care on the surface, but also will not be angry. The C-type personality is not angry on the surface, but not really put out the fire, but deliberately cover up the fire, but in fact the fire is still burning. Usually we can hear “how can a good person like him get cancer” in the oncology dormitory, then the patient is probably a type C personality.