Objective To study the clinical application effectof hair transplantation in repairing postoperative incision scar with expanded scalp flap Methods A total of 35 patients with cicatricial alopecia treated in our hospital from January 2017 to January 2019 were randomly divided into control group (17 cases) and study group (18 cases). The control group received only expanded head flp repair for treatment, and the study group continued to implement hair transplantation after expanded head flp repair. After 2 years of follow-up, the incidence of postoperative scar, hair thinning rate, hair growth uniformity, concentration, appearance score and satisfaction were compared between the two groups. Results The incidence of scar and hair absorption rate in the study group were 5.56% and 5.56%, which were lower than 17.65% and23.53% in the control group (P<0.05). The satisfaction of the study group was 94.44%, which was higher than 76.47% of the control group (P<0.05). The scores of hair growth uniformity, concentration and appearance in the study group were higher than those in the control group (P<0.05). Conclusion The clinical application value of hair transplantation in improving the postoperative incision scar after expanded scalp flaprepair is obvious, which is helpful to reduce the incidence of scar and the sparse rate of hair, and improve satisfaction.