Objective To evaluate the effect of Honghua Xiaoyao tablets combined with compound acid in the treatment of melasma of liver depression and qi stagnation type and its inffuence on Melasma Area and Severity Index. Methods A total of 100 patients with melasma of liver depression and qi stagnation type admitted to the Department of Dermatology, Xuzhou Central Hospital from January 2022 to January 2025 were selected, and they were divided into the control group and the observation group by the random number table method, with 50 patients in each group. The control group was treated with oral Honghua Xiaoyao tablets, and the observation group was treated with oral Honghua Xiaoyao tablets combined with compound acid. The Melasma Area and Severity Index, skin barrier function, psychological state, quality of life and adverse reaction rate were compared between the two groups. Results After treatment, the MASI score of the two groups was lower than that before treatment, and that of the observation group was lower than that of the control group (P<0.05). After treatment, the TEWL of the two groups was lower thanthat before treatment, and that of the observation group was lower than that of the control group (P<0.05). After treatment, the stratum corneum hydration of the two groups was higher than that before treatment, and that of the observation group was higher than that of the control group (P<0.05). There was no statistically signiffcant difference in sebum content between the two groups after treatment (P>0.05). After treatment, the scores of SAS and SDS in the two groups were lower than those before treatment, and those in the observation group were lower than those in the control group (P<0.05). After treatment, the DLQI score of the two groups was lower than that before treatment, and that of the observation group was lower than that of the control group (P<0.05). The incidence of adverse reactions in the observation group was 12.00%, compared with 10.00% in the control group, the difference was not statistically signiffcant (P>0.05). Conclusion Honghua Xiaoyao tablets combined with compound acid has a deffnite effect in the treatment of melasma of liver depression and qi stagnation type. It can effectively reduce the severity of skin lesions, improve the patient's psychological state and skin barrier function, without increasing the risk of adverse reactions.