Abstract: Tumor immunotherapy has changed mode for tumor treatment and has gradually developed into the fourth tumor treatment option after surgery, chemotherapy, and radiotherapy. However, the response rate of immunotherapy is limited. Identification of accurate tumor immunotherapy biomarkers as targets or detection and evaluation indicators would be helpful to improve the response rate. Explorations of more effective delivery of immunotherapy would benefit more patients. Prevention and response to immune-related adverse reactions are also necessary. With the development of research, immunotherapy will bring more hope to cancer patients.