Objective To explore the clinical effect of 308 nm excimer ultraviolet light in the treatment of patients with alopecia areata. Methods A total of 80 patients with alopecia areata admitted to our hospital from October 2018 to October 2023 were selected as the research objects. They were divided into control group and observation group according to the random number table method, with 40 patients in each group. The control group was treated with conventional drugs, and the observation group was treated with 308 nm excimer ultraviolet light on the basis of the control group. The clinical efficacy, complications, treatment satisfaction, alopecia areata area and hair density were compared between the two groups. Results The total effective rate of treatment in the observation group was 97.50%, which was higher than 80.00% in the control group (P <0.05). The incidence of complications in the observation group was 0, which was lower than 12.50% in the control group, the difference was statistically significant (P <0.05). The treatment satisfaction of the observation group was 95.00%, which was higher than 80.00% of the control group, the difference was statistically significant (P <0.05). The area of alopecia areata in the observation group was smaller than that in the control group, and the hair density was higher than that in the control group, the difference was statistically significant (P <0.05). Conclusion 308 nm excimer ultraviolet light is effective in the treatment of alopecia areata, which can effectively improve the symptoms of alopecia areata, reduce the area of alopecia areata, and improve the density of hair. Meanwhile, the incidence of complications after treatment is low, and the safety is high, which is conducive to improving patient satisfaction.