Objective To explore a kind of comfortable medical for ervical plexus anesthesia auxiliary anesthesia .Methods 80 thyroidectomy female patients were randomly divided into normal saline group (group A) ,droperidol-fentanyl group (group B) ,bu-torphanol group (group C) ,dex group (group D) ,20 cases in each group .The change of systolic blood pressure (SBP) ,diastolic blood pressure (DBP) ,heart rate (HR) ,blood oxygen saturation (SpO2 ) ,narcotrend index (NTI) were monitored .The above pa-rameters were recorded at 10 min before cervical plexus(T0 ) ,cervical plexus operation(T1 ) ,skin incision(T2 ) ,separation of thyroid upper extreme(T3 )and suture(T4 ) .Results There was no significant difference between the groups A and B at the same time point (P>0 .05) .In group C ,the SBP、DBP、HR at T3 and T4 were significant higher than at T0 ,and at the same point the A and B group decreased statistically significant (P<0 .05) .In group D ,the SBP、DBP、HR at T2 、T3 、T4 were significant lower than at T1 ,espe-cially at T4 compared to at T0 (P<0 .05) .Compared to group A ,B ,C ,the SBP、DBP、HR in group D were lower at T3 and T4(P<0 .05) .NTI in group D at T1 、T2 had significant difference compared with group A and B (P<0 .05) ,especially at T3 、T4 were sta-tistically significant than the other three groups(P<0 .05) ,sedation was better than the other groups .Conclusion Cervical plexus block supplemented by dex can reduce the patient′s stress response and reach moderate sedation analgesia to comfortable medical purposes .