Objective To investigate the clinical efficacy of photodynamic therapy with red and blue light in the treatment of facial acne. Methods Ninety-two cases of facial acne in dermatology outpatient hospital were randomly divided into the test group and the control group, with 46 cases in each group. Patients in the test group received the photodynamic therapy, and patients in the control group received red plus blue light treatment for eight weeks, respectively. Results Before treatment, patients in the test group and the control group had no significant differences in acne, papules, pustules, nodules, cysts and gags score. After 8-week treatment, the comedones, papules, pustules, nodules cyst number, gags score of patients in the test group were significantly less than or lower than those of patients in the control group (P < 0.05, respectively). The healing rate was 84.78% in the test group, which was higher than that of 65.22%in the control group of (P<0.05). The total efficiency was 97.83%in the test group and 93.48% in the control group, with no significant difference. The adverse reaction rate was 10.87% in the test group and was 23.91% in the control group, with no significant difference. Conclusion The effect of photodynamic therapy for facial acne is better than red plus blue light treatment ,with a less incidence of adverse reactions.