Gut microbiota， as an important environmental factor， plays an important role in the occurrence and development of obesity. Functional oligosaccharides are a class of non-digestible carbohydrates that can inhibit the development of obesity by improving the composition of gut microbiota and the level of metabolites in obese people. In this paper， the mechanism of obesity induced by imbalance of gut microbiota and its metabolites， the effect of functional oligosaccharides on the microecology of intestinal microflora， and the research progress of the underlying mechanism by which functional oligosaccharides inhibit the development of obesity were reviewed.