I. Selection of experimental subjects A total of 68 cases were selected for melasma treatment in our hospital, and randomly divided into two groups. Treatment process Control group: OPT with wavelength 515–1200nm was used for optimized pulsed light treatment, with 4 times as a course of treatment and 3 to 4 weeks interval each time; Treatment group: Optimized pulsed light combined with hydrophobic needle guided tranexamic acid and reduced glutathione was used for treatment. Firstly, OPT treatment was applied to the extent of mild redness and slight warmth of the skin at the lesion site. After an interval of 2 weeks, hydrophotorefractive injection was performed to introduce 1ml of 1% tranexamic acid injection, 0.9g of reduced glutathione injection and 2ml of non-cross-linked hyaluronic acid mixture (mixed well in a three-way tube.) The OPT treatment was alternated with hydrophotorefractive injection, and the treatment interval was 2 weeks. Both groups of candidates underwent a course of treatment for 4 months, with attention to sun protection after the procedure. Follow-up observation of clinical efficacy and adverse reactions, evaluation and comparison. Before and after the treatment, photos were taken for comparison, and the clinical efficacy was evaluated after 1 year of follow-up. The basic cure was considered as the fading of pigmentation spots ≥90% and no recurrence; the obvious fading was considered as the fading of pigmentation spots with color or area reduction ≥60%; the improvement was considered as the fading of pigmentation spots with color or area reduction ≥30%; and the invalidation was considered as the no change of pigmentation spots or lesion fading <30%. The clinical efficacy of the two groups was compared statistically, and the clinical efficiency and recurrence rate of each group were studied and compared. IV. Treatment results The efficacy of 68 patients in this group was evaluated after treatment, and patients in all groups had efficacy. Among them, 2 cases in the control group were basically cured, 11 cases were obviously subsided, 13 cases were improved, and 6 cases were invalid (4 cases recurred 12.5%). The total effective rate was 81.23%; in the treatment group, 5 cases were basically cured, 17 cases were obviously receding, 10 cases were improving, and 4 cases were invalid (2 cases relapsed 5.6%). The total effective rate was 88.9%. After the treatment group, only mild redness and swelling appeared at the needling point, which generally subsided within 24 to 48 hours. No significant adverse reactions occurred after treatment in each group of candidates. V. Conclusion Optimized intense pulsed light is a new generation of intense pulsed light, and its treatment of melasma has fewer adverse reactions, obvious efficacy, no skin damage and fast recovery after treatment. Tranexamic acid and reduced glutathione can improve melasma by inhibiting tyrosinase activity, and non-cross-linked hyaluronic acid can promote the metabolism of skin pigment by replenishing dermal water and repairing skin barrier, and hydraluminescence injection therapy not only avoids the side effects of drug sedation or oral administration, but also promotes the absorption of drugs locally, and achieves certain efficacy in the treatment of melasma. Optimized pulsed light combined with hydro-needle introduction therapy is more effective, especially for deeper and longer lasting melasma, the effect is better than single treatment. The parameters of optimized pulsed light and the density and depth of hydraluminescence needles should be adjusted individually during the treatment to improve the efficacy and reduce the adverse effects. Tips: Melasma is a common acquired pigmented lesion, which is a chronic refractory pigment disorder. In this study, the safety and therapeutic effects of optimized pulsed light and OPT combined with hydro-needle introduction therapy in melasma treatment problems were further explored.