Abstract: Thymic tumors are the most common malignant tumors of the anterior mediastinum. Surgical resection is the main treatment for thymic tumors, but the need for adjuvant radiotherapy after surgery is controversial. For tumors that cannot be completely resected, the role of postoperative radiotherapy is certain. However, for completely resected thymic tumors, deciding on whether to supplement with postoperative radiotherapy depends on the tumor stage and histological type. This article reviews the application of postoperative radiotherapy in the treatment of completely resected thymic tumors.