Objective To analyze the plastic treatment method and clinical treatment effect of skin scar after burn. Methods A total of 100 patients with skin scar after burn admitted to our hospital from January 2020 to January 2022 were selected as the research objects. According to the random number table method, they were divided into experimental group and reference group, with 50 patients in each group. The reference group was treated with skin graft, and the experimental group was treated with skin tissue expander. The clinical efficacy and adverse reactions of the two groups were compared. Results The total effective rate of treatment in the experimental group was 94.00%, which was higher than 64.00% in the reference group, the difference was statistically significant (P <0.05). The incidence of complications in the experimental group was 12.00%, which was lower than 48.00% in the reference group, the difference was statistically significant (P <0.05). Conclusion The skin tissue expander method is effective and safe in the treatment of skin scars after burn, which is worthy of long-term clinical application.