Fucoxanthin is a kind of marine allenic carotenoid with specific structure, which has several biological properties, including anti-oxidation, anti-cancer, anti-obesity and anti-diabetic, etc. It has high nutritional and health value. At present, it has become one of the hot issues in the research and development of marine food nutritional factors. The sources and extraction methods of fucoxanthin, the metabolic and absorption pathways, stability and safety, and other physiochemical properties are summarized, and the functional properties of fucoxanthin, such as anti-oxidation, anti-cancer, anti-obesity, anti-diabetic, and anti-photodamage, are described in depth. The application in food, especially the significant anti-obesity and anti-diabetic activity of fucoxanthin has been thoroughly explained and analyzed. Fucoxanthin mainly regulates mitochondrial uncoupling protein 1 to avoid excessive fat accumulation. In addition, fucoxanthin and its metabolites regulate the expression of fat genes to realize the anti-obesity effect. The anti-diabetic activity is mainly complied by directly down-regulating the expression of adipocyte mRNA or up-regulating the glucose carrier on the mouse skeletal muscle to reduce blood sugar and increase the content of insulin in plasma, which can effectively regulate the blood sugar levels. These information might provide theoretical references for fucoxanthin researchers and further development and utilization of fucoxanthin in the food industry.