Inclusion Criteria:  18 years ≤ age < 55 years ASA classification I ~ II full term (37 weeks ≤ gestational weeks < 42 weeks) fchedule for elective single cesarean section under spinal anesthesia no other clinical trial 3 months before the enrollment volunteer to participate and sign the informed consent form  Exclusion Criteria:  severe preeclampsia or hypertension diabetes cardiac insufficiency mental abnormality or cognitive impairment or inability to communicate acupuncture points skin breakage, infection, allergy the researchers believe that there are any conditions that are not suitable for inclusion.