Objective: To observe the clinical effect of self-made unilateral breast shoulder brake belt in radical mastectomy for breast cancer. Methods: From April 2021 to November 2021, 70 patients with breast cancer underwent unilateral radical mastectomy in our hospital were selected as the control group. Seventy patients with breast cancer who underwent unilateral radical mastectomy in our hospital from December 2021 to July 2022 were selected as the experimental group. Patients of the control group were taken conventional breast pressure bandage + traditional nursing methods. While breast pressure bandage and self-made unilateral breast shoulder brake belt were used in patients of the experimental group. After treatment, the clinical data of the two groups were collected, the drainage volume and comfort score at different time points, the incidence of complications, and the motion range of shoulder joint within 7 days after surgery were compared between the two groups. Results: The motion range of the experimental group after surgery was significantly lower than that of the control group (P＜0.05). The drainage volume at different time points after surgery in the experimental group was significantly less than that in the control group (P＜0.05). The extubation time, length of hospital stay and healing time of the experimental group were significantly lower than those of the control group, and the incidence of complications of the experimental group was significantly less than that of the control group (P＜0.05). The postoperative pain score of the experimental group was significantly lower than that of the control group, and the postoperative comfort score was significantly higher than that of the control group (P＜ 0.05). Conclusion: Using the self-made unilateral breast shoulder brake belt in the initial recovery process of patients who received radical mastectomy for breast cancer could avoid significant complications in recovery, shorten the length of hospital stay and extubation time of patients, accelerate the recovery of surgical incisions and affected limbs, and help patients return to normal life as soon as possible.