Objective:To explore the effect of red and blue light combined with adapalene gel on acne vulgaris. Methods: 120 patients with acne vulgaris were treated in dermatology department from September 1, 2024 to December 30, 2025. They were randomly divided into two groups by double blind method. 60 patients in the observation group were treated with red and blue light combined with adapalene gel, while 60 patients in the reference group were treated with adapalene gel. The severity, aesthetic effect, total effective rate, adverse reactions and recurrence rate of acne were observed. Results: After treatment, the score of Global Acne Grading System (GAGS) in the observation group was lower than that in the reference group (P<0.05), and the aesthetic effect visual analogue scales,VAS) was higher than that in the reference group (P < 0.05). The total effective rate of the observation group was higher than that of the reference group (P<0.05), the incidence of adverse skin reactions was slightly different from that of the reference group (P>0.05), and the recurrence rate of acne after 3 months of follow-up was lower than that of the reference group (P<0.05). Conclusion: The treatment of acne vulgaris with red and blue light combined with adapalene gel has the advantages of high efficiency and safety, and achieves ideal aesthetic effect.