Gastric cancer is divided into early gastric cancer and progressive gastric cancer, and there are various manifestations of gastric cancer CT, as follows: 1. Early gastric cancer is difficult to be detected on CT due to its small lesions, and gastroscopy is needed to diagnose it; 2. Progressive gastric cancer is middle and late gastric cancer, and the cancer invades into the submucosa and even into the muscle layer, which mainly manifests as limited or diffuse gastric wall thickening on CT, and such gastric wall thickening is often Such thickening is often uneven and even ulcers can be seen, and the cancer is locally stiff. If the cancer is large and has grown beyond the stomach wall into the surrounding tissues, for example, it can invade the left lobe of the liver or the pancreas. If there is metastasis, one can see obvious lymph node enlargement metastasis in the abdominal cavity, between the hepatic and gastric ligaments, or lymph node metastasis in the retroperitoneum. Patients with intermediate to advanced disease often have distant metastases, such as liver metastases, which can also be seen as multiple hypodense metastatic lesions in the liver. According to the different manifestations of CT, gastric cancer is divided into four stages. Stage I is a mass confined to the lumen of the stomach without metastasis and without adjacent organ invasion; stage II is a thickening of the stomach wall greater than or equal to 1 cm; stage III is a gastric cancer that has invaded adjacent organs in addition to local manifestations; stage IV is a stage with distant metastasis. Therefore, the diagnosis of gastric cancer can be staged based on CT manifestations, which in turn enables patients to receive the most suitable treatment in clinical practice.