Lung cancer immunotherapy drugs have side effects, but the incidence of immunotherapy-related adverse reactions is relatively low. Because the drug mainly activates the body’s own immune system to kill the organ inflammatory reaction caused by tumor, it produces some adverse reactions, which include the following aspects: 1. endocrine-related toxicity: such as thyroid, pituitary, adrenal and pancreas, mainly manifested as weakness, weight gain or loss, dizziness, syncope, hair loss, fear of cold, constipation; 2. gastrointestinal toxicity: mainly manifested as diarrhea, cramps pain, and in severe cases, blood in the stool may occur; 3, liver toxicity: yellowing of the skin or mucous membranes may occur, nausea and vomiting may occur in severe cases, and if combined with viral hepatitis, may cause abnormal liver function; 4, immune pneumonia: immune pneumonia may occur in the lungs, causing new onset of cough aggravation and respiratory distress; 5, skin and heart-related toxicity. Overall, the adverse reactions that occur are relatively mild, but early detection, treatment and prevention can often improve.