Depression is a chronic mood disorder with high incidence， high relapse rate and high suicide rate. Polysaccharides play an important role in maintaining microbial imbalance and maintaining intestinal barrier integrity in the intestinal tract of living organisms. Polysaccharides also play a crucial role in regulating the homeostasis of intestinal flora and in the life processes of living organisms. The intestinal flora can influence the occurrence and development of depression through the brain-gut axis. This paper reviews the interaction between intestinal flora and polysaccharides， the role of intestinal flora in the brain-gut axis， and explores the role of polysaccharides in regulating intestinal flora in the pathogenesis of depression， with a view to providing reference for the prevention and treatment of depression.