Objective To investigate the therapeutic effect of fasciocutaneous flap plastic repair on children with scar contracture deformity after hand burn. Methods A total of 100 children with scar contracture deformity after hand burn who were treated in Handan Hangang Hospital from January 2020 to December 2021 were selected as the research objects. According to the random number table method, they were divided into control group and observation group, with 50 children in each group. The control group was treated with routine surgery, and the observation group was treated with fasciocutaneous flap plastic repair on the basis of the control group. The clinical effects, scar condition and joint function of the two groups were compared. Results The total effective rate of the observation group was 96.00%, which was higher than 76.00% of the control group (P <0.05). The scar scores of the two groups after treatment were lower than those before treatment, and the observation group was lower than the control group (P <0.05). The excellent and good rate of joint function in the observation group was 92.00%, which was higher than 60.00% in the control group (P <0.05). Conclusion Fasciocutaneous flap plastic repair can effectively improve the clinical effect of scar contracture deformity after hand burn, improve the scar condition, and is conducive to the recovery of joint function.