Gastric cancer is one of the most common malignant tumors in China with high mortality rate, one out of every four deaths due to malignant tumors. Therefore, stomach cancer is a disease that seriously endangers the life and health of our people. The treatment effect of gastric cancer is closely related to the stage of the disease. More than 90% of patients with early gastric cancer can survive for more than 5 years after treatment, while less than 5% of patients with advanced gastric cancer can survive for 5 years. Therefore, how to detect gastric cancer at an early stage is the key to improve the therapeutic effect and increase the survival rate of patients. Screening through the high-risk group is an effective means to detect early gastric cancer. The so-called high-risk group of gastric cancer refers to people who are more likely to develop gastric cancer than the general population, and their incidence rate of gastric cancer is several times or even nearly 10 times higher than that of the general population. Patients with precancerous lesions of gastric cancer: precancerous lesions of gastric cancer refer to benign diseases that have the tendency to change into gastric cancer, and the common ones are as follows: ①, chronic atrophic gastritis, which is the most common type of precancerous lesions, and its chance of occurring gastric cancer can be as high as 10%. ②, chronic gastric ulcer, the cancer rate is generally less than 3%, if the regularity of ulcer symptoms has recently changed, the degree has increased, and there is loss of appetite, vomiting and progressive wasting, attention should be paid to the occurrence of cancer. ③, gastric polyps, it is generally believed that polyps with diameter >2cm, multiple and wider base have high cancer rate. ④, after partial gastrectomy, a lot of information shows that the risk of cancer in the residual stomach after partial gastrectomy increases up to 0.3-10%. ⑤, other precancerous lesions, such as giant gastric mucosal hypertrophy, warty gastritis, etc. 2.Persons with H. pylori infection: Research shows that the rate of H. pylori infection is significantly and positively correlated with the mortality rate of gastric cancer, and the risk of gastric cancer for those infected with H. pylori is 4 times higher than that for those not infected. 3. Those who have bad eating habits: such as irregular diet, eating moldy food, fast eating, pickled and smoked food, high salt diet, and less fresh vegetables. Frequent consumption of moldy food can lead to mold infections such as Aspergillus, Aspergillus and Fusarium in the gastric juice, which produces Aspergillus and aflatoxin, which are strong carcinogens. In addition, cured and smoked foods contain a large amount of carcinogenic substances, which can lead to a higher incidence of gastric cancer if eaten for a long time. High salt diet is also positively correlated with the occurrence of gastric cancer. For example, the incidence of gastric cancer in the United States and New Zealand is very low with a salt intake of 10 grams per person per day, while the incidence of gastric cancer is higher in countries with a salt intake of 12-15 grams per day, and the incidence of gastric cancer is very high in Japan, Finland and most Eastern European countries with a salt intake of more than 15 grams per person per day. At present, it is believed that salt itself is not carcinogenic, but may cause damage to the gastric mucosa, which makes people more susceptible to gastric cancer in collaboration with other carcinogenic factors. 4. Long-term alcoholics and smokers: Alcohol can stimulate the gastric mucosa and change the mucosal cells, leading to the occurrence of gastric cancer. The relationship between smoking and stomach cancer has also been confirmed, and smoking may be a strong risk factor. The risk of gastric cancer in smokers is not only related to the amount of cigarettes smoked, but also to the age at which smoking begins, with the greatest risk occurring when smoking begins in adolescence. It is worth noting that alcohol consumption and smoking can affect the occurrence of gastric cancer independently, but can also have a multiplicative effect, which can significantly increase the risk of gastric cancer. 5. Mentally stimulated and sulking people: In the analysis of risk factors of gastric cancer, it is found that the risk of gastric cancer is significantly higher for those who are sulking, mentally stimulated and depressed for a long time. 6.Family history of gastric cancer or esophageal cancer: There is a family aggregation phenomenon of gastric cancer, and it has been reported that the incidence of gastric cancer among patients’ family members is 2-3 times higher than that of the normal population. It has also been reported that diffuse gastric cancer is related to A blood type. However, it is still not clear how genetic factors play a role in the occurrence of gastric cancer. 7. Certain special occupations: Studies have shown that workers exposed to sulfuric acid dust and mist, lead, asbestos and herbicides, as well as workers in the metal industry have a significantly higher risk of stomach cancer. In conclusion, it is important to clarify the high-risk groups of gastric cancer for the prevention, early detection and early treatment of gastric cancer. Therefore, high-risk groups should actively receive health education and learn relevant knowledge, and neither fear nor pay no attention to the disease. They should take effective preventive measures under the guidance of specialists and formulate reasonable follow-up plans according to the risk level, so as to increase the early diagnosis rate and improve the overall outcome of gastric cancer.