The invention provides a separation and purification method of a human 
umbilical cord mesenchymal stem cell exosome and an application of the human 
umbilical cord mesenchymal stem cell exosome, and belongs to the technical field of medicines. The human 
umbilical cord mesenchymal stem cell exosome provided by the invention is prepared by cultivating human umbilical cord mesenchymal stem cells via aserum-
free medium, collecting supernatant liquid, implementing centrifuging as well as ultra-
filtration and concentration, transferring a concentrated solution onto a 30% 
sucrose-
heavy water densitypad and implementing further purification through 
sucrose density centrifuging, so that the human umbilical cord mesenchymal 
stem cell exosome is obtained. According to the separation and purificationmethod that the human umbilical cord mesenchymal 
stem cell exosome is obtained through separation and purification, immunoreactivity is effectively reduced, and a controllable dosage when the human umbilical cord mesenchymal 
stem cell exosome is used is guaranteed. The human umbilical cord mesenchymal stem 
cell exosome, by improving a degree of activating an 
insulin signaling pathway of a type IIdiabetes 
animal model, can inhibit composition and 
decomposition of 
hepatic glycogen, so that glucose 
metabolism homeostasis can be achieved; and meanwhile, the sensitivity of the 
type II diabetes animal model to 
insulin and an 
insulin secretion function of pancreatic [beta] cells can be improved and a blood glucose concentration can be reduced, so that the application of the human umbilical cordmesenchymal stem 
cell exosome to the preparation of medicines for treating 
type II diabetes can be achieved.