Radiotherapy is mainly used for the comprehensive treatment of inoperable locally advanced pancreatic cancer, the comprehensive treatment of residual or recurrent tumor cases after surgery, and the palliative reduction treatment of advanced pancreatic cancer. 1.Treatment principles. (1) Simultaneous chemoradiotherapy based on 5-fluorouracil or Kenze. (2) For locally advanced inoperable resectable pancreatic cancer without distant metastases, if the patient’s general condition allows, synchronized chemoradiotherapy should be given in the hope of obtaining a chance of surgical resection or prolonging the patient’s survival time. (3) Patients with residual tumor in non-radical resection should be given postoperative chemoradiotherapy. (4) If intraoperative tumor is found to be inoperable or inoperable, intraoperative local irradiation can be considered together with postoperative chemoradiotherapy. (5) Patients without distant metastases after radical resection of pancreatic cancer can be considered for postoperative chemoradiotherapy. (6) In case of inoperable advanced pancreatic cancer with severe abdominal pain or pain caused by metastases in bone or other areas, which seriously affects the quality of life of patients, synchronized chemoradiotherapy or radiotherapy alone can play a good role in palliation and disease reduction if the patient’s physical condition allows. (7) Postoperative synchronized radiotherapy should be carried out after the patient’s physical condition has basically recovered from 4-8 weeks after surgery. (8) Three-dimensional conformal or intensity modulated conformal radiotherapy should be used to improve the accuracy of treatment and to protect the important normal tissues and organs around the pancreas, and conventional radiotherapy can be considered for the palliative reduction treatment of patients with bone metastases. 2. Protection. Using conventional radiotherapy techniques, attention should be paid to the protection of lung, heart, esophagus and spinal cord in order to avoid serious radiation damage to important organs of the body. 3.Effectiveness of treatment. The evaluation of the efficacy of chemotherapy should refer to the WHO criteria for evaluating the efficacy of solid tumors or the RECIST criteria for evaluating the efficacy of chemotherapy.