The so-called cancer body, in terms of genetic structure, has 23 pairs of chromosomes, and the sequencing of genes is very complex. Although the human gene sequence has been basically elucidated by 2001, if any mutation or injury occurs at any locus, a geometric mutation may occur under certain stimulating conditions. The geometric level is also the one that causes malignant changes in the cells, just according to the data of the geometric level of the Nth power of 2 to form a tumor. Cancer body type is not a body type that appears to be very healthy and free of cancer. Cancer body type is often those who are strong, have a regular and healthy life for a long time, but are prone to tumors. Cancer constitution is often related to personality characteristics, such as introversion and extroversion, cheerfulness and gloom. Introverted people are reluctant to talk to others about their sufferings, which can be attributed to cancer personality to a certain extent. The immune barrier is the mechanism that can make the body’s immunity get some balance and coordination, without adapting to it, this immune barrier will collapse in the long run, and what tumor fears most is the immune system, so at this time some psychological changes cause physiological changes, and pathological and physiological changes occur. Therefore, people who are introverted, unwilling to talk about their misery and pain, and deliberately make it difficult for themselves are also considered a type of cancer body.