Objective To explore the effect of Kangfuxin solution in treating flap necrosis and wounds disunion after radical mastectomy. Methods From October 2021 to October 2022, 80 patients who underwent radical mastectomy and had postoperative skin flap necrosis were selected as the research objects. They were divided into observation group and control group by random number table method, with 40 patients in each group. The control group was treated with iodophor dressing change, and the observation group was treated with Kangfuxin solution. The clinical efficacy and clinical indicators of the two groups were compared. Results The total effective rate of treatment in the observation group was 95.00%, which was higher than 85.00% in the control group, and the difference was statistically significant (P<0.05). The appearance time of new epithelium, wound healing time and upper limb rehabilitation activity time in the observation group were shorter than those in the control group, the wound area was smaller than that in the control group, and the VAS score was lower than that in the control group, the differences were statistically significant (P<0.05). Conclusion Kangfuxin solution has a good effect on the treatment of skin flap necrosis after radical mastectomy, which can effectively inhibit the inflammatory reaction at the wound and reduce the pain of patients. Meanwhile, it is beneficial to improve the healing speed, reduce the wound area and improve the healing effect