Objective To explore the application effect of doxycycline combined with red and blue light irradiation in patients with rosacea. Methods A total of 98 patients with rosacea admitted to our hospital from March 2021 to December 2022 were selected as the research objects. They were divided into control group and observation group by random number table method, with 49 patients in each group. The control group was treated with red and blue light irradiation, and the observation group was treated with doxycycline combined with red and blue light irradiation. The clinical efficacy and skin lesion scores of the two groups were compared. Results The total effective rate of treatment in the observation group was 95.92%, which was higher than 79.59% in the control group, and the difference was statistically significant (P<0.05). After treatment, the scores of telangiectasia, papule pustule, pruritus and erythema in the observation group were lower than those in the control group, the differences were statistically significant (P<0.05). Conclusion Doxycycline combined with red and blue light irradiation in patients with rosacea is helpful to improve the skin state and reduce the degree of skin lesions, which is worthy of clinical application.