Unresectable pancreatic cancer, including locally advanced pancreatic cancer (LAPC) and metastatic pancreatic cancer (MPC), is generally considered not suitable for surgical treatment, because surgery cannot improve the prognosis of patients. In recent years, with the development of preoperative treatment (such as chemotherapy and chemoradiotherapy) and surgical techniques (such as arterial, venous reconstruction, and autologous small intestine transplantation), the concept of conversion therapy provides opportunities for surgical resection for some unresectable pancreatic cancer patients. The median survival time of LAPC patients who underwent surgical resection after neoadjuvant therapy was 21.8 to 40.0 months, and the overall prognosis was significantly better than that of the non-surgical group. MPC patients can also be converted to surgical resection after effective systemic treatment. Nevertheless, the conversion therapy of unresectable pancreatic cancer still faces many challenges, including the low effective rate of neoadjuvant treatment, high early recurrence rate, and no unified and effective patient screening and prediction criteria. In the future, with the rapid development of precision medicine and new treatment methods, through multidisciplinary cooperation and continuous clinical research, conversion therapy is expected to bring survival benefits to more patients with unresectable pancreatic cancer.