Abstract: The gastrointestinal tract is the largest organ connecting the human body and the outside world. The gastrointestinal mucosa is not only an important barrier connecting the internal body and the outside world, but also plays a key role in maintaining normal functions of the gastrointestinal tract. The injuries of gastrointestinal mucosal barrier are the common pathogenesis mechanisms in the occurrence and development of gastrointestinal diseases. However, there is still a lack of deep and systematic understanding of gastrointestinal mucosa, especially small intestinal mucosa. In clinical practice, more attentions have been paid to the role of injury factors, but the importance of mucosal protection is ignored. In order to improve the understanding of gastrointestinal mucosa protection and standardize the clinical application of gastrointestinal mucosal protective agents, the Gastrointestinal Hormone and Mucosal Barrier Group, Chinese Society of Gastroenterology, Chinese Medical Association formulated the first expert consensus on gastrointestinal mucosal protection in China, which was offi- cially published at the end of 2021. This paper interprets the background, process and main content of this consensus, so as to raise awareness among medical staff, and standardize clinical diagnosis and treatment.