Referring to the general tumor prevention methods, understanding the risk factors of tumors and developing appropriate prevention and control strategies can reduce the risk of tumors. There are 2 basic clues to prevent the occurrence of tumor, even if tumor has already started to form in the body, they can help the body to improve the resistance, these strategies are described as follows: 1. Avoidance of harmful substances (cancer-promoting factors) is what can help us to avoid or minimize the exposure to harmful substances. Some factors related to the occurrence of tumors are prevented before the onset. In 1988, a report from the United States compared the international situation of malignant tumors in detail and suggested that many known malignant tumors can be prevented in principle by external factors, that is, about 80% of malignant tumors can be prevented by simple lifestyle changes. 2.Improve the immunity of the body against tumors Can help improve and strengthen the immune system of the body to fight with tumors. The focus of our current tumor prevention and treatment efforts should first focus on and improve those factors that are closely related to our lives, such as quitting smoking, eating right, exercising regularly and reducing weight. Anyone who follows these simple, sensible lifestyle practices can reduce their chances of developing cancer. The most important things to improve immune system function are: diet, exercise and worry control. Healthy lifestyle choices can help keep cancer at bay. Maintaining a good emotional state and appropriate physical activity can keep the body’s immune system in optimal condition, which is equally beneficial in preventing tumors and preventing other diseases from occurring. In addition, studies have shown that proper activity not only strengthens the body’s immune system, but also reduces the incidence of colon cancer by increasing the peristalsis of the body’s intestinal system. Here we focus on recognizing some of the issues of diet in preventing tumorigenesis. Some other studies suggest that beta-carotene drug supplementation alone does not reduce the risk of cancer, but on the contrary increases the incidence of lung cancer slightly, however, when beta-carotene is combined with vitamin C, E and other antitoxic substances, its protective effect is shown. The reason for this is that when it is consumed by itself it can also increase the free radicals in the body, in addition there are interactions between different vitamins, studies in both humans and rats have shown that the application of beta-carotene can reduce the level of vitamin E in the body by 40%, a safer strategy is to eat different foods to maintain a balance of vitamins to defend against cancer, as there are some protective factors that we have not found so far. Vitamins C and E are additional anti-tumor substances. They protect against carcinogens in food such as nitrosamines, and vitamin C protects sperm from genetic damage and reduces the risk of leukemia, kidney cancer and brain tumors in their offspring. Vitamin E reduces the risk of skin cancer. Vitamin E has the same anti-tumor effects as vitamin C. It is an anti-toxin and free-radical scavenger. The combined application of vitamins A, C, and E produces better protection against toxins than the individual application. The current research on phytochemistry has attracted widespread attention. Phytochemistry is the chemical substances found in plants, including the vitamins and other substances found in plants. Several thousand chemicals have been found in plants, many of which have anticancer effects. The protective mechanism of these chemicals not only reduces the activity of carcinogens but also enhances the body’s immunity against carcinogens. For example, a cup of kale contains only 50mg of vitamin C and 13U of vitamin E, but its antioxidant activity is equivalent to that of 800mg of vitamin C and 1100U of vitamin E. It can be inferred that the antioxidant effect of fruits and vegetables is much stronger than that of vitamins as we know them. The effect is much stronger than that of vitamins we know. Undoubtedly natural plant products will help in future cancer prevention efforts.