Breast cancer patients do not need to have all of their breasts removed, and the current international trend is to preserve the breast while curing breast cancer. Breast-conserving surgery can ensure a good breast appearance and improve a woman’s self-confidence and quality of life. However, breast-conserving surgery patients must receive radiotherapy, and postoperative radiotherapy can cause breast contracture and shape changes, which affects aesthetics. Clinical studies suggest that the local recurrence of breast cancer after breast-conserving surgery is mainly in the area close to the tumor bed. The introduction of intraoperative radiotherapy in the general surgery breast area of Xuanwu Hospital combines radiotherapy with breast-conserving surgery, which completes radiotherapy to the operated area before closing the surgical incision, ensuring the accuracy of tumor bed localization and the accuracy of radiation dose received, and better protecting the surrounding normal tissues. The main advantages of intraoperative radiotherapy compared with traditional postoperative radiotherapy are as follows: Wang Xiaohui, Department of General Surgery, Xuanwu Hospital, Capital Medical University 1) Better breast appearance: intraoperative radiotherapy can better protect normal breast tissues and increase the dose of local irradiation through precise target localization, and its dose coverage is more uniform, which can obtain better postoperative cosmetic effect. 2) Reduced local recurrence rate: Breast-conserving surgery combined with intraoperative radiotherapy has a lower local recurrence rate because it can target breast tissue in areas with high recurrence. 3) Shorten treatment time: Patients who receive intraoperative radiotherapy can eliminate 5-8 times of postoperative external radiation to the tumor bed, and some patients can even replace 6-7 weeks of postoperative radiation therapy with a single intraoperative radiotherapy session. This provides a more significant convenience for patients who need to receive treatment in the field. 4) Reduce the pain of radiotherapy: intraoperative radiotherapy, the patient is under anesthesia and does not perceive the pain caused by radiotherapy 5) Reduce the overall medical costs: shorter treatment course inevitably reduces medical costs and saves costs. 6) Reduce the occurrence of complications: due to accurate intraoperative positioning, damage to important organs such as the heart and lungs can be avoided. The following is a case of a breast cancer patient who received intraoperative radiotherapy while undergoing breast-conserving surgery in our hospital.