Objective To investigate the effect of compound acid combined with 420 nm intensive pulsed light in the treatment of acne patients. Methods A total of 120 patients with acne admitted to our hospital from April 2022 to February 2024 were randomly divided into reference group and study group, with 60 patients in each group. The reference group was treated with 420 nm intensive pulsed light, and the study group was treated with 420 nm intensive pulsed light combined with compound acid. The clinical efficacy, skin lesion symptom score, skin physiological index and VISIA image analysis score were compared between the two groups. Results The total effective rate of treatment in the study group was 96.67%, which was higher than 78.33% in the reference group (P<0.05). After treatment, the scores of skin lesion type, skin lesion number, skin lesion pain and skin lesion color in the study group were lower than those in the reference group (P<0.05). After treatment, the erythema index, skin elasticity, transdermal water loss and skin layer water content of the study group were better than those of the reference group (P<0.05). After treatment, the VISIA image analysis scores of the study group were lower than those of the reference group (P <0.05). Conclusion 420 nm intensive pulsed light combined with compound acid is effective in acne patients, which can effectively improve the symptoms of skin lesions, regulate the skin state, improve the overall beauty of the skin, and promote the recovery of skin lesions.