Objective To investigate the efficacy of microneedle introduction of human umbilical cord mesenchymal stem cell exosomes in the treatment of sensitive dermatitis and its influence on facial skin barrier function. Methods A total of 60 patients with sensitive dermatitis admitted to Changsha Mylike Medical Cosmetic Hospital from April to November 2023 were selected as the research subjects. According to the random number table method, they were divided into the control group and the treatment group, with 30 patients in each group. The control group received microneedle introduction of hyaluronic acid solution, and the treatment group received microneedle introduction of human umbilical cord mesenchymal stem cell exosomes. The symptom and sign scores, clinical efficacy, skin barrier function, lactic acid sting test score and adverse reactions were compared between the two groups. Results After treatment, the scores of erythema, papules, desquamation, burning sensation, pain, pruritus and tightness in the treatment group were lower than those before treatment and in the control group, and the score of telangiectasia in the treatment group was lower than that in the control group (P <0.05). The total effective rate of treatment in the treatment group was 93.33%, which was higher than 36.67% in the control group (P <0.05). After treatment, the TEWL in the treatment group was lower than that in the control group, and the skin water content was higher than that in the control group (P <0.05). After treatment, the lactic acid sting test score of the treatment group was lower than that of the control group (P <0.05). Both groups had only 2 cases of loca anesthetic allergy (incidence rate: 6.67%), and no serious adverse reactions were observed. Conclusion Microneedle introduction of human umbilical cord mesenchymal stem cell exosomes can improve the clinical symptoms and skin barrier function of patients with sensitive dermatitis, reduce skin sensitivity, and has high safety, which is worthy of clinical application.