High-calorie food intake and unhealthy lifestyle have considerably raised the incidence of obesity. The gut microbiota is associated with metabolic disorders which promote excessive accumulation of fat, elicit host systemic, low-grade chronic inflammation, and insulin resistance. These features make gut microbiota a promising target for the prevention and intervention of obesity. Herbal polysaccharides in TCM are uneasy to digest by the host, but can be decomposed and utilized by the intestinal flora as the carbon source to mediate bacterial composition. In this review, we are describing the therapeutic effect of polysaccharides on the imbalanced structure of gut microbiota and its metabolites, and discuss the research progress that has been made to unravel the underlying mechanism by which polysaccharides of TCM inhibit the onset and development of obesity.