Immunotherapy has become a milestone in the field of tumor treatment by strengthening host immune system to attack cancer cells. However, with widespread application of immunotherapy, the incidence of immune-related adverse events (irAEs) has been increased significantly. IrAEs can involve multiple organs and systems, such as skin, heart, digestive system and endocrine system, which can be life-threatening in severe cases and significantly affect the quality of life and clinical prognosis of patients. Most symptoms can be relieved by terminating medication for mild to moderate irAEs. Glucocorticoids are still the first-line treatment drugs for severe IRES, while anti-TNF-α drugs are effective for hormone-refractory cancer. Although studies have revealed the correlation between genetic factors, gut microbiota and cytokine levels and the risk of irAEs, precise prediction and diagnosis still face challenges. In this article, research progress in epidemiological characteristics, potential mechanism, prediction and treatment of irAEs was systematically reviewed, aiming to provide reference for clinical practice.