In-vitro expansion method of NK (Natural Killer) cells

The method comprises the following steps: resuspending mononuclear cells by using an activated culture medium, adding the resuspended mononuclear cells into a cell culture plate coated with CD16 and NKp46 antibodies, culturing for more than 21 days, culturing by using the activated culture medium in the first to fourth days, and performing fluid infusion culture by using an amplification culture medium from the fifth day; the activated culture medium is obtained by adding autologous plasma, IL2, IL15, IL18, IL21 and IL27 on the basis of an NK cell amplification serum-free culture medium; the amplification culture medium is obtained by adding autologous plasma and IL2 on the basis of an NK cell amplification serum-free culture medium. The CD16 and NKp46 antibodies are combined with the coated cell culture plate, meanwhile, five cell factors such as IL2 and IL15 are added to synergistically stimulate the NK cells and induce differentiation and maturation of the NK cells, and the obtained NK cells are high in pu