OBJECTIVE：To observe the a nesthetic effect and safety of dexmedetomidine combined with butorphanol for laparoscopic radical resection of colorectal cancer. METHODS ：Totally 180 patients undergoing elective laparoscopic radical resection of colorectal cancer were selected from our hospital during Apr. 2019-May 2020. They were randomly divided into control group（group C ），dexmedetomidine group （group D ），butorphanol group （group B ），dexmedetomidine+butorphanol group （group E），with 45 cases in each group. Group C received rountine anesthesia of Etomidate emulsion injection+Sufentanil citrate injection+ Cisatracurium besylate for injection. Group D was given Dexmedetomidine injection 0.5 μg/kg by pumping 15 min before induction ， and received rountine anesthesia indution performed in group C. Group B was given intravenous injection of Butorphanol tartrate injection 0.02 mg/kg when anesthesia indution ，and received rountine anesthesia performed in group C. Anesthesia induction in group E was the same as that in group D+B. The dosage of sufentanil and the maintenance concentration of sevoflurane were observed；average arterial pressure （MAP）and heart rate （HR）at the time of entering the room （T0），1 min after intubation （T1）， 1 min after skin incision （T2），and 5 min after extubation （T3），extubation time ，Ramsay sedation score 5 min after extubation and VAS score ，the occurrence of ADR were recorded. RESULTS ：One patient in group C and two patients in Group E were excluded due to the conversion of laparoscopic surgery to open surgery. The rest of the patients completed the study. At T 1-T3，MAP and HR in group C ，D and B were significantly higher than those at T 0（P＜0.05），while there was no significant difference in MAP or HR in group E at T 1-T3，compared with those at T 0（P＞0.05）. MAP of group D and B at T 1-T2 as well as MAP of group E at T 1-T3 were significantly lower than that of group C ，the order was group E ＜group B ＜Group D （except for group B compared with group D at T 3）；HR of group D and E at T 1-T3 as well as that of group B at T 1-T2 were significantly lower than group C ，and the order was group E ＜group B ＜Group D （except for group B compared with group D at T 3）（P＜0.05）. The amount of sufentanil and VAS score of group B ，D，E were significantly lower than that of group C ，and the order was group E ＜group B ＜group D ， VAS score of group E ＜group D ，B（P＜0.05）. The maintenance concentration ，extubation time ，nausea and vomiting ，the incidence of agitation during recovery period in group E were significantly lower or shorter than group C ，D，B. Ramsay sedation score was significantly higer than group C ，D and B. The nausea and vomiting ，the incidence of emergence agitation in group E ＜ group D ，B（P＜0.05）. There was no statistical significance in the maintenance concentration of sevoflurane ，Ramsay sedation score or extubation time among group C ，D and B ，VAS score ，the incidence of nausea and vomiting ，the incidence of agitation during recovery period between group D and B （P＞0.05）. CONCLUSIONS ：Dexmedetomidine combined with butorphanol can effectively reduce the amount of intraoperative anesthetics and the occurrence of stress reaction ，improve the quality of resuscitation，and reduce the incidence of postoperative ADR.