Objective To analyze the efficacy and safety of ultra-pulsed carbon dioxide (CO2) laser in the treatment of facial pigmented nevus. Methods A total of 190 patients with facial pigmented nevus admitted to Changzhou Xinbei District Luoxi Town Health Center from January 2022 to October 2024 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 95 patients in each group. The control group was treated with surgical resection, and the observation group was treated with ultra-pulsed carbon dioxide laser. The scar condition, clinical efficacy, VAS scores and adverse reactions were compared between the two groups. Results The scar formation rate of the observation group was lower than that of the control group (P <0.05). There were no significant differences in the total effective rate of treatment, the one-time cure without recurrence rate and the two-time cure without recurrence rate between the observation group and the control group (P >0.05). The VAS scores of the two groups decreased gradually at 6, 12, and 24 hours after surgery, and those of the observation group were lower than those of the control group (P <0.05). The incidence of adverse reactions in the observation group was 5.26%, which was lower than 13.68% in the control group (P <0.05). Conclusion Compared with surgical resection, the ultra-pulsed carbon dioxide laser has a lower scar formation rate, less postoperative pain, and a lower incidence of adverse reactions in the treatment of facial pigmented nevus.