Pathological biopsy of the reddened gastric mucosa is aimed at clarifying the nature of the diseased tissue and helping to determine whether malignant changes have occurred. The redness of gastric mucosa is generally considered to be caused by inflammation. When gastric wall hyperplasia and gastric mucosal lesions appear during gastroscopy, such as severe erosion and ulceration of gastric mucosa, or when the patient’s condition lasts for a long time and the gastric mucosa has hyperplasia of abnormal color, it is recommended to perform pathological biopsy in order to clarify the nature of the lesions and to determine the presence or absence of gastric cancer. Pathological biopsy can not only accurately determine the nature of the lesions, but also help to formulate a treatment plan, and once diagnosed as malignant, surgical treatment is recommended. Pathological biopsy of gastric mucosa should be performed under the guidance of a doctor and standardized diagnosis and treatment.