Currently, all thymomas are considered malignant. The need for radiotherapy after surgery for thymoma is related to the stage of the disease. stage I lesions that are completely resected generally do not require adjuvant radiotherapy, and postoperative radiotherapy is generally recommended for lesions that are not completely resected in other stages. Radiotherapy plays an important role in the treatment of thymoma. Studies have shown that postoperative radiotherapy has therapeutic benefit in patients with selective thymoma. Stage I: Postoperative adjuvant therapy is not recommended after complete resection of thymoma; postoperative radiotherapy is recommended for those with incomplete resection of the lesion. Stage II: For complete resections, international guidelines recommend postoperative radiotherapy, which can be decided after thorough discussion with the physician. For incomplete resection, postoperative radiotherapy is recommended. Stage III to IVA: support the postoperative administration of adjuvant radiotherapy. Whether or not radiotherapy is needed after surgery for malignant thymoma is recommended to be decided by a specialist after comprehensive assessment according to the specific condition.