PD-1 immunotherapy is currently a popular treatment in the medical field, its Chinese name is programmed death molecule, and PD-1 is phonetically translated from English, its main basis is that immune cells, i.e. T cells have PD-1 binding receptors on them, and then tumor cells have PDL-1, i.e. ligands, on top of them, and after the binding of receptors and ligands it leads to a decrease in the ability of T cells to kill tumor cells. Therefore, the production of the drug is to block the binding of PD-1 and PDL-1, thus enhancing the ability of T cells to kill tumor cells.