In recent years, the incidence of rectal cancer has been increasing and has become the third most dangerous malignant tumor disease to human health. Rectal cancer refers to the cancer between the dentate line and the junction of rectosigmoid colon, which is one of the most common malignant tumors of the gastrointestinal tract. It is usually found to be treated surgically, but because of its location deep into the pelvis and complex anatomical relationship, surgery is not easy to be complete and the recurrence rate after surgery is high. Its etiology is also related to dietary structure, so it is extremely important to pay attention to postoperative dietary health care of rectal cancer. The etiology of rectal cancer is still not very clear, and its development is related to social environment, dietary habits, genetic factors and so on. It is basically recognized that high intake of animal fat and protein and insufficient intake of dietary fiber are high risk factors for rectal cancer, and rectal polyps are also high risk factors for rectal cancer. Post-operative dietary care for rectal cancer is based on balanced nutrition and support for deficiency. Internal deficiency” of rectal cancer patients is the main contradiction in the process of disease occurrence and development. The deficiency causes cancer, and the deficiency causes deficiency because of cancer, and the deficiency contains the real, and the deficiency is the root. The purpose of dietary therapy is to ensure that rectal cancer patients have sufficient nutritional supplements, improve the body’s ability to resist disease and promote the recovery of patients. Dietary health care should be nutritious, diversified and balanced. One of the causative factors of rectal cancer is the unreasonable dietary structure, and the food consumed is mainly high sugar, high protein, high fat and low dietary fiber, so the following principles must be followed in the post-operative diet of rectal cancer: 1. Patients with colon and rectal cancer have recurrent and persistent diarrhea, and their digestive ability is weak, so they should be given food that is easy to digest and absorb. 2. Patients with colorectal cancer mostly have blood in stool, and late stage patients often have a lot of blood in stool, so they should take less or no stimulating and spicy food. 3.Patients with prolonged diarrhea or late stage patients have long term fever, sweating and damage to fluid, so it is appropriate to drink more water or soup, and the main food can be mainly semi-liquid diet such as porridge and noodles. 4.Patients mostly have symptoms such as loss of appetite, nausea and even vomiting, so it is appropriate to take light diet and avoid greasy. 5.Patients with advanced colorectal cancer have prolonged diarrhea, blood in stool, fever, large amount of nutrients and water loss, emaciation, weight loss, and deficiency of both blood and gas, so it is appropriate to take nutritious tonic juice diet. After rectal cancer surgery, the patient’s diet should be mainly high-calorie, high protein and high vitamin. High-calorie food is mainly starchy food (such as potatoes), but should not eat more high-fat food; high protein food includes various kinds of fine meat, milk, fish, soy products, etc.; fresh vegetables and fruits are the main source of vitamins and fiber. Chicken, eggs and seafood are commonly known as “hairy foods”, but in fact there is no place for them in the list of dietary contraindications. In the early postoperative period, you should eat less and more meals, and not eat pickled and moldy foods. The early resumption of physical activity (such as limb movement in bed) after surgery is beneficial to promote the recovery of intestinal function and prevent urinary retention and deep vein thrombosis in the lower extremities, but should not be rushed. In the early postoperative period, patients can participate in activities with little physical activity such as jogging and tai chi, and then start to exercise as usual after their physical strength has fully recovered, but generally they should not do strenuous exercises. Physical activity is not only beneficial to patients’ physical recovery, but also helps patients to rebuild their self-confidence and maintain a happy mood, thus improving the anti-tumor ability of their own organism.