Objective To analyze the effect of triethanolamine on postoperative radiation dermatitis of breast cancer. Mehtods A total of 120 patients with breast cancer who received surgical treatment in Jinan Third People's Hospital from January 2018 to January 2024 were retrospectively selected, all of whom received postoperative radiation therapy. The patients were grouped by random envelope method, and only 60 patients who received radiogenic therapy were used as the control group, and 60 patients treated with triethanolamine were added as the observation group. The incidence of radiation dermatitis during radiotherapy, the interruption rate of unplanned radiotherapy and the recovery of radiation dermatitis at 1 week after radiotherapy were compared between the two groups. Results (1) The time of complication of radiation dermatitis in observation group was later than that in control group, and the severity of radiation dermatitis in this group was less than that in control group (P<0.05). (2) At the 5th week of radiotherapy, the interruption rate of unplanned radiotherapy in the observation group was lower than that in the control group (P<0.05). (3) One week after radiotherapy, the recovery of radiation dermatitis in observation group was better than that in control group (P<0.05). Conclusions For patients with postoperative radiotherapy for breast cancer, continuous use of triethanolamine during radiotherapy can effectively reduce the severity of radiation dermatitis, reduce the risk of unplanned radiotherapy interruption due to complications, and promote the recovery of radioactive dermatitis.