Objective To explore the effect of fiber optic lipolysis technology in contour shaping of patients with facial and neck fat relaxation. Methods From February 2021 to February 2024, 60 patients with facial and neck fat relaxation admitted to the Department of Cosmetic Surgery of Zhang Ruihong Medical Cosmetic Clinic were selected as the research objects. They were randomly divided into control group and experimental group, with 30 patients in each group. The control group was given traditional treatment, and the experimental group was treated with fiber optic lipolysis technology. The clinical related indexes, scar recovery quality and complications were compared between the two groups. Results The operation time, wound healing time and ecchymosis regression time of the experimental group were shorter than those of the control group, and the VAS score was lower than that of the control group (P <0.05). The quality of scar recovery in the experimental group was better than that in the control group (P <0.05). The incidence of complications in the experimental group was 6.67%, which was lower than 23.33% in the control group (P <0.05). Conclusion The application of fiber optic lipolysis technology in the contour shaping of patients with facial and neck fat relaxation is effective, which can effectively shorten the operation time and postoperative recovery time, improve the quality of scar recovery, and the incidence of postoperative complications is low, with high safety.