Objective To analyze the effect of oral Chushi Qingre decoction combined with external Zhiyang lotion on clinical symptoms in patients with scalp seborrheic dermatitis. Methods A total of 112 patients with scalp seborrheic dermatitis (damp-heat syndrome) admitted to the Department of Dermatology, Qinhuai District Fuzimiao Community Health Service Center from March 2024 to August 2025 were selected, and they were divided into group A and group B by the random number table method, with 56 patients in each group. Group A was treated with external 2% ketoconazole lotion, and group B was treated with oral Chushi Qingre decoction combined with external Zhiyang lotion. The treatment effect, clinical symptoms and quality of life were compared between the two groups. Results The total effective rate of group B (91.07%) was higher than that of group A (75.00%) (P<0.05). The scores of scalp greasiness, erythema, scales, itching and total score in the two groups after treatment were lower than those before treatment, and those in group B were lower than those in group A (P<0.05). The DLQI score in the two groups after treatment was lower than that before treatment, and that in group B was lower than that in group A (P<0.05). Conclusion Oral Chushi Qingre Decoction combined with external Zhiyang lotion has a good effect in the treatment of scalp seborrheic dermatitis (damp-heat syndrome), which can effectively improve the clinical symptoms of patients and help to reduce the adverse effects of the disease on their quality of life.