Research on melasma and skin microbiota is relatively scarce. The aim of this study is to investigate the efficacy of QCWC as a drug in the treatment of melasma and its impact on the local skin microecology. A total of 60 skin microbiome samples were collected, and 16S rRNA gene sequencing was used to explore the relationship between melasma and the skin microbiota. The results of this study will help to better understand the composition of skin microbiota in melasma and the changes in diversity and composition during treatment, providing further evidence for the efficacy and safety of QCWC in the treatment of melasma.