Gastric cardia intraepithelial neoplasia is a precancerous lesion that occurs in the cardia. The gastric cardia is a part of the stomach that connects to the esophagus, and it is a part of the gastric mucosa that is prone to lesions. Under the condition of chronic inflammation, chemical stimulation and pathogenic stimulation, mucosal epithelial cell lesions can occur, causing cell heterogeneity, cell arrangement, irregular cell nuclei of different sizes, and increased nucleoplasma ratio, and the diagnosis of the pathology results suggests that intraepithelial neoplasia is a precancerous lesion. After the occurrence of gastric cardia intraepithelial neoplasia, if it is not controlled in time, further development of gastric cancer may occur, which requires standardized treatment under the guidance of clinicians. Therefore, patients with high risk of gastric cancer should have their stomach checked regularly.