Objective To explore the effect of Q-switched laser on the incidence of scars in patients with facial nevus pigmentosus. Methods A total of 86 patients with facial nevus pigmentosus admitted to the Department of Dermatology, the First People's Hospital of Sihong County from January 2024 to May 2025 were selected as the research subjects, and they were divided into the control group and the observation group by the random number table method, with 43 patients in each group. The control group was treated with carbon dioxide laser, and the observation group was treated with Q-switched laser. Both groups received fractional laser treatment at 2 weeks after the initial treatment. The incidence of scars, skin condition, quality of life and inffammatory indicators were compared between the two groups. Results The incidence of scars in the observation group after treatment (4.65%) was lower than that in the control group (23.26%) (P<0.05). The scores of redness, swelling, itching and pain in the observation group after treatment were lower than those in the control group (P<0.05). The scores of quality of life in the observation group after treatment were higher than those in the control group (P<0.05). The levels of tumor necrosis factor-α and interleukin-8 in the observation group after treatment were lower than those in the control group (P<0.05). Conclusion In the clinical treatment of facial nevus pigmentosus, the application of Q-switched laser can reduce scar formation, effectively improve the overall skin condition, thereby enhancing the patient's quality of life and helping to reduce the levels of related inffammatory factors.