Abstract: Objective　To explore the effect of red and blue light combined with Adapalene gel in the treatment of mild and moderate acne. Methods　From May 2018 to may 2019, 150 patients with mild to moderate acne were randomly divided into two groups. The patients in the experimental group (n=75) were treated with alternating red and blue light combined with Adapalene gel, and the control group (n=75) was treated with Adapalene gel. The treatment period was 1 month. Results　There was no significant difference in sex, age, blood pressure, liver function and renal function between the experimental group and the control group (P>0.005), but there were significant differences in hemoglobin (P<0.05). There was no significant difference in Leeds score between the experimental group and the control group before treatment (P>0.05); After one month of treatment, Leeds score in the experimental group was significantly lower than that before treatment (P<0.05), while Leeds score in the control group had no significant difference(P>0.05). After 1 month of treatment, the number of healing in the experimental group was significantly higher than that in the control group, and the overall effective rate was also significantly higher than that in the control group (P<0.001). Conclusion　Red blue light irradiation combined with Adapalene gel can significantly improve the appearance of patients with mild and moderate acne, and the treatment effect is obvious and safe.

Key words: Acne, 　Treatment, 　Red and blue light irradiation