To prevent the occurrence of cancer, we should pay attention to the following aspects: 1. Change the bad life and behavior, the first and foremost is to quit smoking and drinking, because the occurrence of many malignant tumors in the body is related to smoking and drinking. 2. Prevent the occurrence of cancer through reasonable diet and physical activity, such as eating less food rich in protein and fat, especially fried food, and eating more vegetables and fruits containing fiber, etc. 3. 3. Controlling weight gain and maintaining a certain amount of regular physical activity can also effectively prevent the occurrence of cancer. 4. Reducing exposure to carcinogenic factors in occupational environment. 5. Preventing tumors caused by biological factors, such as preventing hepatitis B through hepatitis B vaccination to reduce the occurrence of liver cancer, and preventing cervical cancer through human papilloma virus vaccination. virus vaccine to prevent the occurrence of cervical cancer, etc.