Objective To explore the effect of alternating red and blue light irradiation combined with collagen dressing on facial aesthetic effect and acne improvement effect in acne patients. Methods A total of 80 acne patients admitted to Afffliated Hospital of Jiangnan University from May 2024 to June 2025 were selected, and they were divided into the control group and the observation group by the random number table method, with 40 patients in each group. The control group was treated with collagen dressing, and the observation group was treated with alternating red and blue light irradiation on the basis of the control group. The facial aesthetic effect, acne improvement effect, recurrence rate, quality of life and adverse reaction rate were compared between the two groups. Results The excellent and good rate of facial aesthetics in the observation group (92.50%) was higher than that in the control group (70.00%) (P<0.05). The excellent and good rate of acne treatment and recurrence rate in the observation group were better than those in the control group (P<0.05). The scores of each dimension of quality of life in the observation group after treatment were higher than those in the control group (P<0.05). There was no signiffcant difference in the incidence of adverse reactions between the two groups (P>0.05). Conclusion The application of alternating red and blue light irradiation combined with collagen dressing for acne patients can improve the excellent and good rates of facial aesthetics and acne treatment, reduce the recurrence rate, and improve the quality of life, without increasing the risk of adverse reactions.