Abdominal CT can detect gastric cancer, but the specificity is not high. The most reliable examination of gastric cancer is gastroscopy combined with pathological biopsy. CT of gastric cancer can show localized thickening or mass of stomach wall, accompanied by enhancement or signal abnormality. Gastroscopy with biopsy is the gold standard for gastric cancer. Early stage gastric cancer has rough mucosa, easy to bleed when touched, patchy congestion and erosion, if it lacks of specificity, multi-point biopsy is needed. If there is a lack of specificity, multi-point biopsy is needed. The surface of progressive gastric cancer is often uneven, and there is no peristalsis at the lesion, for ulcerative lesions, multi-point biopsy can be performed at the lower edge and base. CT can be used as auxiliary staging diagnosis of gastric cancer, and pathological biopsy is necessary to confirm the diagnosis, so early diagnosis and early treatment can maximize the quality of life.