To investigate the effect of Xiaofeng Baihu decoction in the treatment of patients with facial allergic dermatitis of blood-heat and wind-dryness type. Methods A total of 80 patients with facial allergic dermatitis of blood-heat and wind-dryness type admitted to the Department of Dermatology, Donghai County Hospital of Traditional Chinese Medicine from June 2021 to June 2023 were selected as the research objects. They were divided into control group and observation group by random number table method, with 40 patients in each group. The control group was treated with desloratadine orally combined with dexamethasone acetate for external use. The observation group was treated with modified Xiaofeng Baihu decoction on the basis of the control group. The levels of inflammatory factors, cellular immune function, TCM syndrome scores, clinical efficacy, treatment satisfaction and adverse reactions were compared between the two groups. Results After treatment, the levels of IL-2 and IL-6 in the observation group were lower than those in the control group (P <0.05). The level of CD4+ in the observation group was higher than that in the control group, and the level of CD8+ was lower than that in the control group (P <0.05). The scores of TCM syndromes in the observation group were lower than those in the control group (P <0.05). The total effective rate of treatment in the observation group was 97.50%, which was higher than 80.00% in the control group (P <0.05). The treatment satisfaction of the observation group was 100.00%, which was higher than 77.50% of the control group (P <0.05). The total incidence of adverse reactions in the observation group was slightly lower than that in the control group, but the difference was not statistically significant (P >0.05). Conclusion Xiaofeng Baihu decoction is effective in the treatment of facial allergic dermatitis of blood-heat and wind-dryness type, which can effectively alleviate the inflammatory reaction, and has good safety and high patient satisfaction