Objective To analyze the aesthetic effect of carbon dioxide fractional laser combined with glycolic acid in patients with acne scar. Methods A total of 40 patients with acne scar admitted to our hospital from June 2023 to December 2024 were selected, and they were divided into the control group and the observation group according to the random number table method, with 20 patients in each group. The control group was treated with glycolic acid, and the observation group was treated with carbon dioxide fractional laser combined with glycolic acid. The local skin physiological function, aesthetic effect and recovery time were compared between the two groups. Results The transepidermal water loss of the observation group after treatment was (13.43±1.43)g/(h?m2), which was lower than that of the control group [(16.54±1.32)g/(h?m2)] (P <0.05). The stratum corneum hydration of the observation group after treatment was (48.32±1.23)%, which was higher than that of the control group [(42.43±1.28)%] (P <0.05). The skin sebum secretion of the observation group after treatment was (157.54±1.23)μg/cm2, which was lower than that of the control group [(206.54±1.27)μg/cm2] (P <0.05). The ECCA score of the observation group after treatment was (28.43±1.76)scores, which was lower than that of the control group [(32.43±1.65) scores] (P <0.05). The skin melanin index score of the observation group was (195.43±13.45)scores, which was lower than that of the control group [(223.43±13.37)scores] (P <0.05). The pain duration, erythema duration, skin incrustation time and decrustation time in the observation group were shorter than those in the control group (P <0.05). Conclusion Carbon dioxide fractional laser combined with glycolic acid can effectively imp rove the skin physiological function of patients with acne scar , enhance the skin aesthetic effect, and shorten the recovery cycl e, which is worthy of clinical application.