In recent years, the synthesis of human milk oligosaccharides (HMOs) in vitro has developed rapidly, but its industrialization process has lagged behind. In order to explore its causes, this paper introduced lots of research results on the synthesis of HMOs at home and abroad in the decades. The results showed that: the whole cell fermentation synthesis method was currently recognized as the most industrialized potential of the production of breast milk oligosaccharides, at the same time, the price of L-fucose limited the industrial development of HMOs largely. Nowadays, the source of L-fucose still mainly was extracted from natural products and there were some problems such as single raw materials and high extraction costs. In future, other more ways for producing L-fucose should be developed, such as constructing a high-yield L-fucose strain by means of biotechnology, and extracting L-fucose from agricultural waste resources also has a good application prospect.