JAK2-STAT3 signaling pathway, as the main chain of intracellular signal transmission, plays an important role in cell proliferation, apoptosis, invasion, migration and immune response. Triggered by cytokines and interferon, this pathway can quickly transduce extracellular signals into the nucleus, and it has abnormal expression in various tumors, such as squamous cell carcinoma of the head and neck, lung cancer, esophageal cancer, gastric cancer, liver cancer, breast cancer and myeloproliferative neoplasms. Further understanding of the carcinogenic mechanism of JAK2-STAT3 signaling pathway can provide new ideas for clinical treatment of tumors and prognosis.