Objective To analyze the effect of carbon dioxide fractional laser in the treatment of children with early hypertrophic scar after deep burn. Methods A total of 60 children with early hypertrophic scar after deep burn admitted to Gansu Provincial Hospital from January 2023 to December 2024 were selected as the research subjects, and they were divided into the control group and the analysis group by the random number table method, with 30 children in each group. The control group was given conventional treatment, and the analysis group was given carbon dioxide fractional laser treatment on the basis of the control group. The VSS score, OSAS score and adverse reactions were compared between the two groups. Results After treatment, the scores of color, thickness, softness and vascular distribution in the analysis group were lower than those in the control group (P <0.05). The scores of each dimension of the OSAS in the analysis group after treatment were lower than those in the control group (P <0.05). The incidence of adverse reactions in the analysis group (6.67%) was lower than that in the control group (26.67%) (P <0.05). Conclusion The introduction of carbon dioxide fractional laser is effective in the treatment of children with early hypertrophic scar after deep burn, which is beneficial to effectively improve their scar condition, reduce the degree of itching and pain, and reduce the incidence of adverse reactions.