Objective To explore the effect of personalized forehead flap repair based on 3D reconstruction technology for nasal defect on aesthetic effect. Methods A total of 120 patients with nasal defect admitted to our hospital from January 2023 to May 2024 were selected as the research subjects. According to the random number table method, they were divided into the control group and the experimental group, with 60 patients in each group. The control group received traditional empirical flap repair, and the experimental group received personalized forehead flap repair based on 3D reconstruction technology. The nasal aesthetic effect, repair effect and pain degree were compared between the two groups. Results The scores of nasal symmetry, contour smoothness, proportion coordination, nasal tip shape, nasal alar width and skin color matching in the experimental group were higher than those in the control group (P <0.05). The repair effect score in the experimental group at 1, 3, and 5 months after surgery was better than that in the control group (P <0.05). The VAS score in the experimental group at 6, 24, and 48 hours after surgery was lower than that in the control group (P <0.05). Conclusion The personalized forehead flap repair for nasal defect based on 3D reconstruction technology has a good effect. It can improve the repair effect and aesthetic satisfaction, and reduce postoperative pain.