Objective To analyze the improvement effect on periorbital skin aging after adding CO2 fractional laser with different parameters based on type A botulinum toxin. Methods A total of 70 patients diagnosed with periorbital skin aging and admitted to Shenzhen Second People's Hospital from February 2023 to February 2025 were included. According to the random envelope method, they were divided into group A (n =35) and group B (n =35). Both groups were treated with the JZ-1C type carbon dioxide laser treatment machine, but with different parameters. Group A was treated with type A botulinum toxin combined with CO2 fractional laser with parameters of 30 mJ and 4%, and group B was treated with type A botulinum toxin combined with CO2 fractional laser with parameters of 50 mJ and 8%. The cosmetic improvement effect, skin barrier function (transepidermal water loss, stratum corneum hydration, skin sebum content) and VISIA skin image scores were compared between the two groups. Results The excellent and good rate of skin cosmetology in group B was 97.14%, which was higher than 71.43% in group A (P <0.05). After treatment, the level of transepidermal water loss in group B was lower than that in group A, and the stratum corneum hydration and skin sebum content were higher than those in group A (P <0.05). After treatment, the scores of VISIA skin image in group B were lower than those in group A (P <0.05). Conclusion Compared with the CO2 fractional laser with parameters set as 30 mJ and 4%, the combination of CO2 fractional laser with parameters of 50 mJ and 8% and type A botulinum toxin has a better cosmetic effect, which can better improve the skin barrier function and the symptoms of periorbital skin aging.