Objective To explore the effect of TCM facial mask combined with Zhigancao decoction based on the "internal and external combined therapy" theory on skin lesions in patients with rosacea of Heat-Toxin accumulated in the skin type. Methods A total of 60 patients with rosacea admitted to the Department of Dermatology of Suzhou 100 Hospital from January to December 2025 were selected as the research subjects. According to the random number table method, they were divided into the control group and the observation group, with 30 patients in each group. The control group was given oral Zhigancao decoction, and the observation group was given oral Zhigancao decoction combined with external application of TCM facial mask. The skin lesion symptoms, clinical efffcacy and skin barrier function were compared between the two groups. Results After 4 weeks of treatment, the scores of erythema, papules, pustules, telangiectasia and total skin lesion score in the observation group were lower than those in the control group (P<0.05). The total effective rate of the observation group (93.33%) was higher than that of the control group (73.33%) (P<0.05). After 4 weeks of treatment, the TEWL of the observation group was lower than that of the control group (P<0.05). Conclusion Based on the theory of "internal and external combined therapy", the combination of TCM facial mask and Zhigancao decoction can alleviate skin lesions in patients with rosacea of Heat-Toxin accumulated in the skin type, effectively improve skin barrier function, and obtain favorable clinical efffcacy.