Objective To investigate the effects of cranial electrotherapy stimulation on perioperative anxiety in patients undergoing radical mastectomy. Methods A total of 86 patients undergoing radical mastectomy were randomly divided into intervention group（n = 43）and control group（n = 43）. The intervention group was treated with cranial electrotherapy stimulation for five times：2 and 1 day before operation，right before operation at the waiting chamber，1 and 3 days after operation，20 minutes each time，while the control group was given sham stim⁃ ulation in the same way at the same time points. State⁃trait anxiety inventory and Athens Insomnia Scale were used to evaluate the patients′ anxiety and state of sleep at 2 days before operation（T1），right before operation at the waiting chamber（T2），1 day（T3），3 days（T4）and 7 days（T5）after operation，and the intraoperative conditions and postoperative adverse reactions were observed. Results There were no statistically significant differences between the two groups in terms of the preoperative baseline levels，intraoperative conditions，and incidence of postoperative adverse events. At T2，T3，T4，and T5，the scores of anxiety and insomnia in the intervention group were significantly lower than those of the control group（P < 0.05）. Conclusion Cranial electrotherapy stimulation has a positive effect in alleviating perioperative anxiety of patients undergoing radical mastectomy and can effectively improve patients′ sleep quality. This technique provides evidence for perioperative non⁃drug interventions in anxiety and poor sleep of patients undergoing radical mastectomy.