Patients were randomly assigned to three groups, receiving 30min TEAS before anesthesia respectively. The acupoints of dual point group are bilateral Neiguan points(PC6) combined with Danzhong point(RN17), single point group is bilateral Neiguan points(PC6), and the false stimulation group only attach electrodes without electric current. The frequency of TEAS is set to 2/15 Hz. Intraoperative anesthetic dosage of propofol and remifentanil was recorded. Three and six months after surgery, follow-up about chronic pain was made by telephone or face-to-face using the follow-up questionnaire. The adverse events were recorded.