Short-chain fatty acids are metabolites produced by dietary fiber in foods fermented by intestinal flora, mainly organic fatty acids and their salt compounds containing 1-6 carbon atoms. Intestinal flora imbalance is associated with diarrhea. Changes in intestinal flora composition caused changes in intestinal short-chain fatty acid content. More and more studies have shown that short-chain fatty acids play an important role in the occurrence and treatment process of diarrhea. This paper introduces the origin and composition of short-chain fatty acids, and reviews the effect of short-chain fatty acids on diarrhea based on intestinal energy metabolism, intestinal mucosal barrier function, intestinal immune function as well as intestinal electrolyte and water absorption, so as to provide references for the diagnosis and treatment of diarrhea.