Akkermansia muciniphila (A. muciniphila) is a normal flora of human gastrointestinal tract. The A. muciniphila abundance of intestinal flora in obese patients is significantly decreased. Many evidences suggest that A. muciniphila is negatively related to obesity, diabetes, cardiovascular diseases and low-grade inflammation. A. muciniphila not only plays a metabolic protective role by protecting the integrity of intestinal epithelial cells and mucus layer, but also plays an anti-inflammatory role by regulatory T cells, endogenous cannabinoid system and non-classical Toll-like receptor in the process of inflammatory reaction. This article reviews the relationship between A. muciniphila and obesity, and the molecular mechanism and application of A. muciniphila in obesity.