Objective To explore the effect of Q-switched laser combined with nano-microneedle introduction of tranexamic acid on MASI score in patients with melasma. Methods A total of 106 patients with melasma admitted to the Department of Dermatology, Central Hospital of Qinghe County from January 2024 to January 2025 were selected, and they were divided into the control group and the observation group by the random number table method, with 53 patients in each group. The control group was treated with Q-switched laser, and the observation group was treated with Q-switched laser combined with nano-microneedle introduction of tranexamic acid. The MASI score, clinical efficacy, skin condition and adverse reaction rate were compared between the two groups. Results The MASI score of the observation group after treatment was lower than that of the control group (P<0.05). The total effective rate of the observation group (94.34%) was higher than that of the control group (75.47%) (P<0.05). The scores of skin condition in the observation group after treatment were lower than those in the control group (P<0.05). There was no statistically signiffcant difference in the incidence of adverse reactions between the two groups (P>0.05). Conclusion The combination of Q-switched laser and nano-microneedle introduction of tranexamic acid can enhance the clinical improvement of melasma. This combined scheme can effectively reduce the MASI score of patients, show good effects in regulating epidermal pigmentation and dermal vascular abnormalities, and has controllable treatment safety.