Abstract: Objective To explore the application effects of enhanced computed tomography (CT) and three-dimensional reconstruction technology in the reconstruction of pediatric post-burn scars with expanded flaps. Methods From May 2016 to March 2019, 19 children with hypertrophic scars after thermal injuries were admitted to our unit, including 10 boys and 9 girls, aged from 4 years and 5 months to 15 years and 11 months. The area of scars ranged from 5 cm×4 cm to 23 cm×9 cm. One or more skin and soft tissue expanders with suitable volume and shape were implanted into the normal skin area around scar of children. Three to six months later, enhanced CT and three-dimensional reconstruction were performed before the second stage operation to obtain three-dimensional images of the vascular branches in the donor site for expanded flaps to be cut, so as to determine the course and distribution of the vascular branches and guide the design of expanded flaps. According to the design scheme, the resection of scar, removal of expanders, and excision and transfer of flaps were performed to repair the wounds after scar resection. The area of flaps ranged from 6 cm×4 cm to 25 cm×10 cm. The donor site was closed directly. The number of flaps was counted. The anatomical structure, vascular distribution, and adverse reactions during enhanced CT and three-dimensional reconstruction of site for expanded flaps to be cut, the survival of expanded flaps and the follow-up after the second-stage operation were observed. Results A total of 48 expanded flaps were designed and excised in 19 children. The anatomical structure of the site for expanded flaps to be cut and the adjacent spatial position relationship were visually observed through the three-dimensional reconstruction after enhanced CT, and no adverse reactions were observed. Arterial branch blood supply or venous return was observed in 29 sites for expanded flaps to be cut. All the expanded flaps survived well without blood supply disorder after the second stage operation. The children were followed up for 6 months to 1 year and 6 months after the second stage operation. The appearance of the flaps was natural, and the color and thickness of the flaps were similar to those of the surrounding normal skin, except for one child with obvious linear scar. Conclusions Enhanced CT and three-dimensional reconstruction can assist the vascular assessment of the expended flaps, which is helpful for rational design of the flap excision and transfer protocol to improve the survival rate of flaps. Thus, it has certain clinical application value in the reconstruction of post-burn scar in children with expanded flaps.