Most patients with gastric cancer may have 1-2 or even more tumor indicators, but not all patients with gastric cancer will have high tumor indicators. However, not all gastric cancer patients have high tumor indexes. Some patients with gastric cancer or even advanced metastasis may not have high tumor indexes, but some of them may not necessarily have gastric cancer after repeated examinations. Because the specificity and sensitivity of the tumor indicators used nowadays are not very high, only the combination of tumor indicators, such as CA199, CEA and CA724, can improve the sensitivity and accuracy after the combination of multiple tumor indicators. It is not possible to diagnose gastric cancer simply based on one tumor index. The final diagnosis of gastric cancer should be made through gastroscopy and corresponding pathological tests, and tumor markers play a very important reference role.