Abstract: Recent studies home and abroad have confirmed that these extracellular proteins have the function of enhancing mucosal barrier,regulating immune and maintaining intestinal homeostasis. And to a certain extent,these also can improve,relieve and treat intestinal diseases. The relevant exposition of probiotics secreted extracellular proteins on the intestinal mucosal immune function and the impact on the health has become a research focus. In order to explore the molecular basis of probiotics on the functional barrier of intestinal mucosal barrier and mucosal immune signal,the intestinal mucosal system and its immune mechanism and the role of probiotics in the secretion of extracellular proteins were first summarized,and then the domestic and foreign research on probiotics secreting extracellular proteins was highlighted,and the opinion that extracellular proteins would break through the intestinal mucosal immune signal pathways and played a role in the treatment of intestinal diseases so as to achieve the purpose of maintaining intestinal health was put forward in this article. At the same time,it also put forward a viable approach for research and development to solve the problem of intestinal health.