Objective To investigate the effect of Pipa Qingfei decoction combined with red and blue light therapy on acne severity in patients with facial acne vulgaris. Methods A total of 200 patients with facial acne vulgaris admitted to the Department of Dermatology, Chengxian People’s Hospital of Gansu from January to December 2025 were selected as the research subjects. According to the random number table method, they were divided into group A and group B, with 100 patients in each group. Group A was given red and blue light monotherapy, while group B was given Pipa Qingfei decoction on the basis of red and blue light therapy. The clinical efficacy, acne severity and serum inflammatory indicators were compared between the two groups. Results After 4 weeks of treatment, the GAGS score in group B was lower than that in group A (P <0.05). The total effective rate of group B was higher than that of group A (P <0.05). After 4 weeks of treatment, the serum levels of TNF-α, IL-6 and IL-1β in group B were lower than those in group A (P <0.05). Conclusion The Pipa Qingfei decoction combined with red and blue light in the treatment of facial acne vulgaris not only has good clinical effects, but also can alleviate the acne symptoms of patients and down-regulate the levels of serum inflammatory indicators, thus exerting better anti-inflammatory effects.