Since the cause of rectal cancer is not fully understood. Therefore, there is no special prevention method so far. The main purpose is to reduce the chance of cancer and to detect patients early and treat them early. 1. Develop good dietary and living habits, try to eat less fried, smoked, high-fat and high-protein food, do not eat fruits, vegetables and foods that may be corrupted, and should eat more yams, sweet potatoes, corn, fruits, fresh vegetables and other foods rich in carbohydrates and coarse fibers, which have a short residence time in the intestine and are conducive to the discharge of intestinal toxins. Increase exercise appropriately, maintain a regular rhythm of life, quit smoking and control alcohol, and control weight. 2.For people with high incidence of rectal cancer, they should have regular medical checkups and actively treat primary diseases. Such as active treatment of inflammatory bowel disease, clonorchiasis, ulcerative colitis, microscopic resection of colorectal polyps, etc. Those with a family history of multifamilial polyposis should start screening at the age of 12 to 14. 3, actively prevent and control rectal polyps, anal fistula, anal fissure, ulcerative colitis and chronic intestinal inflammatory stimulation; for multiple polyps, papillary polyps, once the diagnosis is clear, should be early surgical removal to reduce the chance of cancer. 4.Diversify diet, develop good eating habits, do not be partial or picky, do not consume high-fat and high-protein diet for a long time, and often eat fresh vegetables containing vitamins and fiber, which may play an important role in cancer prevention. 5.Prevent constipation and keep the bowel movement smooth. 6. Pay great attention to the regular cancer screening, pay attention to self-examination, improve vigilance and timely diagnosis and treatment after discovering “warning signals”, so as to improve the survival rate of rectal cancer by early detection and early treatment.