Objective To explore the effect of AOPT-LTL mode intense pulsed light on the Melasma Area and Severity Index in patients with melasma. Methods A total of 64 patients with melasma admitted to Wuxi Youkeli Medical Aesthetic Clinic from January 2025 to June were selected as the research subjects. According to the random number table method, they were divided into the conventional group and the study group, with 32 patients in each group. The conventional group was treated with traditional intense pulsed light, and the study group was treated with AOPT-LTL mode intense pulsed light. The Melasma Area and Severity Index (MASI), skin color score, Erythema Index (EI), Melanin Index (MI) and adverse reaction rate were compared between the two groups. Results After treatment, the MASI score of the study group was lower than that of the conventional group (P<0.05). After treatment, the skin color score of the study group was lower than that of the conventional group (P<0.05). After treatment, the EI and MI of the study group were lower than those of the conventional group (P<0.05). The incidence of adverse reactions in the study group was lower than that in the conventional group (P<0.05). Conclusion The application of AOPT-LTL mode intense pulsed light in the treatment of melasma can effectively improve the Melasma Area and Severity Index, reduce EI and MI, with high treatment safety. Meanwhile, it is conducive to improving the overall skin color.