Gastrointestinal tumors, usually referring to malignant tumors, i.e. cancer, include: esophageal cancer, gastric cancer, colorectal cancer, liver cancer, pancreatic cancer, bile duct cancer, etc., which are common and frequent cancers. The incidence of gastric cancer in China reaches 400,000 new cases per year, accounting for 41% of the world incidence; the incidence of colorectal cancer has risen to the third of global malignant tumors, with 130,000 new cases of various intestinal cancers found each year; while the incidence of liver cancer is still rising, with more than 350,000 new cases per year, accounting for half of the world. Early symptoms of digestive tract malignancies are often atypical, and often we think of ourselves as commonly known as gastritis, gastric ulcer, indigestion, constipation, etc., and do not go to hospital for treatment, thus delaying treatment. Some people may have symptoms such as epigastric pain or nausea and vomiting, which can be temporarily relieved after treatment as gastritis or gastric ulcer, but the symptoms will recur within a short period of time, while colorectal cancer often has the earliest symptoms of change in bowel habits and stool properties, which are mostly manifested as increased number of bowel movements, diarrhea, constipation and stool with blood, pus or mucus. Abdominal pain is also one of the early symptoms, which is often a persistent vague pain with inaccurate localization, or abdominal discomfort or bloating. Gastrointestinal tumors in the middle and late stages can be characterized by typical symptoms such as inability to eat, vomiting, anemia, emaciation and the appearance of abdominal masses. For people over 40 years old and those with family history of tumor, they should pay attention to the above mentioned early symptoms and seek medical attention in time for early diagnosis and treatment in order to get good treatment effect. The occurrence of gastrointestinal tumor is closely related to lifestyle. With the development of economy and the change of people’s lifestyle, how to prevent gastrointestinal tumor in life while people are enjoying good food? First, pay attention to dietary habits (1) to promote good eating habits. Do not eat too hard and too coarse food, coarse food should be made fine, soft but not hard. Don’t eat too fast, don’t eat too hot, so as not to stimulate and damage the esophageal mucosa. Eat regularly and quantitatively to avoid hunger and satiety. Change the habit of mainly meat and high-protein food, because high fat, high animal protein on the one hand will stimulate bile secretion, so that the amount of bile in the intestine increases, resulting in increased bile acid and cholesterol content in the stool. (2) Improve food processing and cooking methods. The freshness of food is an important factor in ensuring gastrointestinal health. Try to minimize pickles, salted fish, smoked sausage, ham, etc. These foods are made or cooked with carcinogenic substances such as nitrate, nitrite, nitrosamines and polycyclic aromatic hydrocarbons, and the high concentration of salt can seriously damage the mucosa of the gastrointestinal tract, which is a high-risk factor for the occurrence of gastrointestinal tumors. (3) Don’t eat moldy and spoiled food. Peanuts, rice, corn, soybeans, sorghum are easily contaminated by aflatoxin, and once these things are moldy, many metabolites such as aflatoxin, penicillin and trichothecene are powerful carcinogens, the most dangerous of which is aflatoxin B1. (4) Improve the nutritional structure of diet. The nutritional composition of various foods, especially the vitamins and trace elements contained are different, and there are many varieties of foods, such as more vegetables, fruits and mixed grains, can balance the nutrients needed by the body and avoid the lack of certain types of vitamins or trace elements. 2010 World Cancer Awareness Day advocates that: insisting on eating 80 grams~100 grams of fruits or vegetables daily can reduce the risk of stomach cancer by 30%; on average The average intake of 27 grams of high fiber per day can reduce the risk of bowel cancer by 20%. Do not smoke and drink less. In addition to the close relationship between smoking and lung cancer, it also plays a role in promoting digestive system cancers such as esophageal cancer, stomach cancer and cardia cancer. Actively treat digestive system diseases. Chronic esophagitis, reflux esophagitis, esophageal white spots, polyps, gastric ulcer, chronic atrophic gastritis, epithelial hyperplasia of gastric mucosa, gastric polyps, chronic enteritis, various intestinal polyps (especially adenomatous polyps) and other diseases are likely to induce cancer, so they should be treated urgently and some of them should be considered for surgical treatment to be alert to the occurrence of cancer.