PD-1, clinically known as PD-1 inhibitor, belongs to a kind of immunosuppressive molecule and is a novel drug for the treatment of tumors. This drug can activate T cells, B cells, and monocytes in the patient’s body, and can also cause the patient’s own T cells to be reactivated in order to enhance the immunocidal ability of T cells and strengthen the effect of fighting against tumors. Currently, it is mainly used to treat melanoma, renal cell carcinoma, bladder cancer, and non-small cell lung cancer. In clinical studies, some adverse reactions may occur, including fatigue, weakness, diarrhea, rash and pruritus, etc. A few patients develop renal insufficiency, pneumonia and hypothyroidism, but most patients can be cured of adverse reactions after treatment. However, it is important to be alert to the less common serious adverse reactions in PD-1 immunotherapy, such as myocarditis, hepatitis, pneumonia, and other adverse reactions, some of which may be life-threatening if left untreated. In response to poor response to single drug therapy, it can usually be used in combination with other drugs. Although adverse reactions exist after the use of this drug, they are generally manageable, and PD-1 inhibitor immunotherapy has become a more effective mode of treatment for tumors. Therefore, it is recommended to choose the appropriate modality and drug for treatment under the guidance of a doctor, taking into account your own situation.