The invention provides a preparation method of bispecific
chimeric antigen receptor gene modified natural killer cells, comprising the features: constructing a bispecific
chimeric antigen receptor gene containing specific-binding signaling
lymphocyte activation molecule family member 7 and
fibronectin mutants, recombining the bispecific
chimeric antigen receptor gene to a
viral vector, transfecting with human natural killer cells, and highly expressing the bispecific chimeric
antigen receptor gene, thus specifically binding
tumor cells that express the signaling
lymphocyte activation molecule family member 7 and
fibronectin mutants, inhibiting expression of
natural killer cell inhibitory receptors, and preventing
immune escape of
tumor cells; meanwhile, activating a first
signal and a co-stimulatory
signal to trigger toxic activity of the
tumor cells, and great anti-tumor killing
toxicity is shown in in-vivo and in-vitro experiments; the invention also provides a kit for the preparation of autologous natural killer cells through the above method, and with the kit, it is possible to highly express the bispecific chimeric
antigen receptor gene and trigger great anti-tumor effect.