NK cell therapy, known as natural killer cell therapy, is an important category of tumor immunotherapy and belongs to a type of conventional cell therapy. The key to NK cell therapy is the generation of sufficient numbers of immune cells to recognize and kill tumors, and the ability of effector cells to reach the tumor site, be activated around the tumor, and be able to exert anti-tumor effects. anti-tumor effects. In addition to being able to kill tumor cells, they can also replace the impaired immune function caused by chemotherapy or improve it. Currently, the main problems of NK cell therapy are the low multiplication rate, the difficulty of cell source, and the low cytotoxicity, which limit the clinical application.