Human milk oligosaccharides have received widespread attention due to their unique probiotic effects. The composition and structure of oligosaccharides from the milks of different mammals are different. Some probiotics represented by bifidobacteria evolve a relatively complete metabolic mode of milk oligosaccharides. Compared with other prebiotics, milk oligosaccharides show more health benefits such as inducing the colonization of bifidobacteria and increasing the diversity of intestinal flora.