To observe the clinical effect of transcutaneous electrical cranial-auricular stimulation on mild-to-moderate depression.Methods:A total of 140 patients with mild-to-moderate depression treated in the Guang'anmen Hospital of China Academy of Chinese Medical Sciences from December 2019 to December 2020 were enrolled and randomly divided into an observation group(n=69) and a control group(n=71).The patients in the observation group were treated by electrical stimulation at auricular vagus nerve and Yintang(EX-HN 3)-Baihui(GV 20) by Hwato SDZ-IIB Electronic Acupuncture Stimulator Machine,and those in the control group were administered with Escitalopram Oxalate Tablets for eight weeks.The scores of Montgomery-Asberg Depression Rating Scale(MADRS),Hamilton Depression Rating Scale(HAMD-17),and Hamilton Anxiety Rating Scale(HAMA) were observed at the 0,2nd,4th,and 8th weeks of treatment in both groups.The scores of Pittsburgh Sleep Quality Index(PSQI) in both groups were evaluated at the 0,4th,and 8th weeks of treatment.The clinical efficacies of the two groups were compared after treatment.Results:1) The scores of MADRS,HAMD-17,HAMA,and PSQI decreased in both groups after eight weeks of treatment as compared with those before treatment(P<0.01). 2) After eight weeks of treatment,the observation group was superior to the control group in improving MADRS and HAMD-17 scores(P<0.05). 3) There were no significant differences in the total effective rate and clinical cure rate between the two groups(P>0.05).The observation group was equivalent to the control group in improving the depression of patients with mild-to-moderate depression. 4) The observation group showed no adverse events,which was superior to the control group.Conclusion:Transcutaneous electrical cranial-auricular stimulation can improve the depressed mood of patients with mild-to-moderate depression without adverse events,drug dependence,and other side effects.Therefore,it can serve as an effective approach against depression in patients with mild-to-moderate depression.