Objective To explore the effect of filiform needle acupuncture on skin lesion condition and skin barrier function in chloasma patients. Methods A total of 180 patients with chloasma admitted to Hangzhou Liantianmei Medical Cosmetology Hospital from February 2023 to January 2024 were selected and randomly divided into control group and observation group, with 90 patients in each group.The control group was treated with drugs, and the observation group was treated with filiform needle acupuncture on the basis of the control group. The skin lesion condition, skin barrier function, treatment effect, TCM syndrome scores and adverse reactions were compared between the two groups. Results The MASI score in the observation group after treatment was lower than that in the control group (P <0.05). The sebum content and stratum corneum hydration in the observation group after treatment were higher than those in the control group, and TEWL and pH were lower than those in the control group (P <0.05). The total effective rate in the observation group was 97.78%, which was higher than 86.67% in the control group (P <0.05). The TCM syndrome scores in the observation group after treatment were lower than those in the control group (P <0.05). The incidence of adverse reactions in the observation group was 4.44%, which was lower than 14.44% in the control group (P <0.05). Conclusion The treatment effect of filiform needle acupuncture on chloasma patients is good, which can effectively improve their skin lesion condition and skin barrier function, and help to reduce the symptoms. Furthermore, the risk of adverse reactions is low, and the efficacy and safety of the treatment are high, which is worthy of clinical application.