Objective To explore the application value of modiffed rhombic ffap repair in the treatment of facial soft tissue defect and its influence on scar severity. Methods A total of 78 patients with facial soft tissue defect admitted to Jinan Hospital of Integrated Traditional Chinese and Western Medicine from January 2024 to January 2025 were selected, and they were divided into the reference group (39 patients) and the observation group (39 patients) by the random number table method. The reference group was treated with conventional skin graft repair, and the observation group was treated with modiffed rhombic ffap repair. The perioperative indicators, scar severity, satisfaction and complications were compared between the two groups. Results The incision length and wound healing time of the observation group were shorter than those of the reference group, and the skin defect area was smaller than that of the reference group (P<0.05). The scores of color, thickness, vascular distribution and pliability in the observation group were lower than those in the reference group (P<0.05). The satisfaction rate in the observation group (94.87%) was higher than that in the reference group (79.49%), and the incidence of complications was lower than that in the reference group (P<0.05). Conclusion Modiffed rhombic ffap repair has a good application effect in the treatment of facial soft tissue defect. It has the advantages of small incision and fast healing, which can reduce the severity of facial scars, with a low risk of postoperative complications and high patient satisfaction.