Objective: To investigate the effects of combined treatment with Platinum PicoSure laser and polylactic acid (PLA) microneedling on skin barrier function and the Melasma Area and Severity Index (MASI) in patients with melasma. Methods: A total of 152 patients with melasma admitted to our hospital between June 2023 and June 2025 were selected and divided into a study group (n=76) and a control group (n=76) using a randomized controlled table method. The control group received treatment with the Platinum PicoSure laser, while the study group received combined treatment with the Platinum PicoSure laser and PLA microneedling. The clinical efficacy of the two groups was compared, along with their effects on facial aesthetic outcomes, skin barrier function, and MASI scores. Adverse reactions were also recorded. Results: In the study group, the total effective rate was significantly higher in the study group than in the control group (93.42% vs. 82.89%, P<0.05). After 12 weeks of treatment, both groups of patients showed a significant decrease in MASI score, percutaneous water diversion loss, melasma area, EI, and MI, while sebum content and stratum corneum water content increased. The improvement of skin barrier function in the study group was better than that in the control group (P<0.05). Conclusion: The combined treatment of Platinum PicoSure laser and PLA microneedling can effectively enhance skin barrier function, improve skin texture, remove pigmentation, and increase facial aesthetic outcomes in patients with melasma, demonstrating good safety and efficacy.