Endoscopic ultrasound, CT of chest, abdomen and pelvis, abdominal imaging, laparoscopic exploration and PET-CT can be done to confirm the staging of gastric cancer. 1. Endoscopic ultrasound: gastric cancer patients can understand the infiltration depth of primary tumor through endoscopic ultrasound, which helps to determine the primary tumor stage. 2. Thoracic, abdominal and pelvic CT: thoracic, abdominal and pelvic enhanced CT can help to know the metastasis in chest, perigastric lymph node metastasis and pelvic implantation metastasis, and help to determine the regional lymph node metastasis and distant metastasis. 3. Abdominal imaging: abdominal ultrasound can assess the abdominal organs, especially the sensitivity of liver assessment is better, which can help to know whether liver metastasis occurs in gastric cancer. Abdominal CT or abdominal ultrasound can be supplemented with abdominal nuclear magnetic examination when liver metastasis is suspected, and abdominal nuclear magnetic examination has certain sensitivity for smaller liver metastasis. 4. Laparoscopy: When peritoneal lesions are suspected by abdominal CT, abdominal MRI and other related examinations, peritoneal implantation metastasis can be detected by laparoscopy. 5. PET-CT: When systemic metastasis is suspected, whole-body PET-CT examination can be performed to understand the extent and degree of tumor involvement. The above examinations can help to obtain the primary tumor infiltration, regional lymph node metastasis and distant metastasis. For a specific patient, certain items of the above examinations may be selected, or all of them may be selected. In case of discomfort, prompt medical attention is recommended, and it is advisable to choose the staging test that is suitable for the individual patient under the guidance of the doctor.