Objective To explore the effect of immediate repair of breast defect by adjacent flap transfer in breast conserving surgery for breast cancer in the upper inner quadrant. Methods A total of 90 patients with breast cancer admitted to Zhangqiu District People's Hospital of Jinan from July 2021 to April 2022 were selected as the research objects. According to the random number table method, they were divided into observation group and control group, with 45 cases in each group. The control group received modified radical mastectomy for breast cancer, and the observation group received breast conserving surgery for upper quadrant breast cancer. The treatment satisfaction, clinical efficacy, surgical indicators and quality of life were compared between the two groups. Results The total satisfaction rate of the observation group was 95.56%, which was higher than 80.00% of the control group (P