The invention discloses a method for encapsulated osteoblasts to support and regulate the in-vitro amplification of cord blood hematopoieticstem/progenitorcells (He) in the hypoxia condition, belonging to the fields of biotechnology and tissue TSPCS engineering. The method is characterized in that the human osteoblasts are embedded by gelatin-alginate-chitosan (GAC) microcapsule as matrix feeder cells and co-cultured with the cord blood HSPCs in the 5% hypoxia environment to obtain the HSPCs. The invention adopts GAC microcapsule to separate the human osteoblasts from the cord blood HSPCs to avoid the cell contamination and immunological rejection. Furthermore, the pore passages of the microcapsule are capable of causing hemopoietic growth factors secreted by the osteoblasts in the microcapsule to expand to the habitat of the HSPCs and play a role of stimulating the amplification of the hematopoietic stem/progenitor cells. Moreover, the material of the microcapsule has the slow release function to the expansion of the growth factors to increase the concentration gradient of the growth factors on the surface of the microcapsule, which is helpful for the long-term function of the growth factor. In addition, the microencapsulated osteoblasts form the 3D environment, which not only causes the culture system to contain more osteoblasts, but also causes the culture system to have bigger HSPCs-OBs action area compared with the co-culture pattern of the osteoblasts cultured by adherence. Besides, in the 5% hypoxia environment, the co-culture system is capable of better simulating the hematopoietic microenvironment iche of human bone marrow the osteoblasts have significant effects on the characteristic maintenance and number amplification of stem cells of the HSPCs.