PD-1 immune drugs can be used in the treatment of more than ten types of malignant tumors, such as lung cancer, kidney cancer, head and neck cancer. PD-1, i.e. programmed death receptor 1, can cause tumor cells to undergo immune escape during the process of cancer development, which in turn prevents patients from producing immune killing effects on cancer cells, leading to tumor development. Therefore, PD-1 inhibitors, i.e. immunotherapy in cancer treatment, have been developed. This therapy can improve the patient’s own anti-cancer immunity to achieve the purpose of killing tumor cells, with the advantages of small side effects and good efficacy. Currently, there are more than ten FDA-approved indications for PD-1 in the clinic, including lung cancer, kidney cancer, head and neck cancer, bladder cancer, melanoma, breast cancer, liver cancer, gastric cancer, esophageal cancer, colon cancer, Hodgkin’s lymphoma and so on. The medication should be applied under doctor’s guidance, and should not be used without authorization to avoid adverse consequences.