Objective To investigate the effect of optimized laser treatment parameters on scar improvement in patients with facial post-burn hypertrophic scar treated with non-ablative fractional laser. Methods A total of 60 patients with facial post-burn hypertrophic scar admitted to the Second People's Hospital of Yibin from January 2021 to June 2024 were selected as the research subjects. According to the random number table method, they were divided into the control group and the experimental group, with 30 patients in each group. Both groups received non-ablative fractional laser treatment, the control group was given conventional laser treatment parameters, and the experimental group was given optimized laser treatment parameters. The scar improvement and treatment effect were compared between the two groups. Results The scores of colour, softness, vascular distribution and thickness in the experimental group at 3 and 6 months after treatment were lower than those in the control group (P <0.05). The scores of pruritus, flexibility, pain and abnormal sensation in the experimental group at 3 and 6 months after treatment were lower than those in the control group (P <0.05). The total effective rate of treatment in the experimental group (93.33%) was higher than that in the control group (73.33%) (P <0.05). Conclusion Optimized laser treatment parameters in non-ablative fractional laser treatment can effectively improve the scar condition of patients with facial post-burn hypertrophic scar, with good treatment effect.