After gastroscopy confirms the diagnosis of gastric cancer, patients should also do corresponding imaging examination and biochemical indexes, clinically, patients can be given double lung CT, abdominal ultrasound, abdominal CT, and if there are conditions, they can also do whole-body PETCT, as well as blood biochemical examination. Once gastric cancer patients are diagnosed, they should see whether there are metastases in the abdominal cavity and lungs through auxiliary examinations. The hemoglobin level in blood routine can indirectly reflect whether the patient has severe anemia due to gastric cancer, including biochemical tumor-related factors, which can further evaluate the severity of gastric cancer. It can be a very effective basis for the treatment plan after diagnosis of gastric cancer, therefore, gastroscopy should be conducted under the guidance of doctors for gastric cancer.