Objective To analyze the effect of red and blue light combined with glycolic acid therapy on skin physiological parameters in patients with mild to moderate acne. Methods A total of 120 patients with mild to moderate acne admitted to the Fourth Outpatient Department of Guangzhou Dermatology Hospital from January to December 2024 were selected. According to the random number table method, they were divided into the control group and the observation group, with 60 patients in each group. The control group received glycolic acid therapy, and the observation group received red and blue light combined with glycolic acid therapy. The skin physiological parameters, skin lesion symptoms, quality of life and adverse reaction rate were compared between the two groups. Results After treatment, the R2, stratum corneum hydration and quality of life score in the observation group were higher than those in the control group, while the EI, TEWL, GAGS score and skin lesion score were lower than those in the control group (P<0.05). The incidence of adverse reactions in the observation group (5.00%) was lower than that in the control group (16.67%) (P<0.05). Conclusion Red and blue light combined with glycolic acid therapy for patients with mild to moderate acne can improve skin barrier function, effectively alleviate symptoms, reduce the severity of skin lesions, improve skin quality, and has a low incidence of adverse reactions, which is conducive to improving patients' quality of life.