The causes of malignant tumors including lung cancer are not very clear at present, but psychological factors are unanimously considered to have a great relationship with the development of cancer. A lot of clinical studies have shown that negative emotions such as frequent anger, depression and depression may reduce the immune function of patients through the neurological and humoral systems and affect the immune system’s recognition of malignant tumors, creating favorable conditions for the occurrence of malignant tumors. The above negative emotions are known as C-shaped personality in psychology, and the capital letter C is the initial letter of the English word Cancer. People with C-shaped personality have significantly higher incidence of lung cancer, breast cancer and other cancers than other people. Therefore, in order to prevent lung cancer, maintaining a happy and open mind is as important as quitting smoking and alcohol. Of course, getting angry once in a while does not increase the chance of lung cancer, but it is mainly bad to get angry often.