Backgroud: To evaluate the optimal administration time of butorphanol in suppressing sufentanil-induced cough(SIC) during the induction of general anesthesia.Methods:180 patients were randomly divided into 4 equally sized groups: at 5min, 2min and 0min before anesthesia induction, all patients were sequentially injected the drug labeled A/B/C (butorphanol 1mg or normal saline), GI received intravenously drug A/B/C (All were normal saline),GII received intravenously drug A/B/C (A was butorphanol, B and C were saline), GIII received intravenously drug A/B/C (B is butorphanol, A and C were saline), GIV received intravenously drug A/B/C (C is butorphanol,A and B were saline). ALL Patients were then administrated with sufentanil 0.4 µg/kg in 5s after drug C. The incidence and severity of SIC was recorded within 2 minutes after sufentanil injection. MAP, HR, and SpO2 were recorded at T0 (before the administration of any drug),Ta, Tb, Tc (before the injection of drug A/B/C), T1( 2minutes after sufentanil injection) and T2 (1 minutes after endotracheal intubation). Results: The incidences of cough in GII, GIII, and IV were lower than that in GI (0.09, 0.01, and 0 vs 42.2%, P<0.01), while there were no significant differences between GII, GIII, and GIV. The HR of all 4 groups at T2 were significantly higher than their levels at any other time (P<0.05,T2 vs other time), but there’s no significant difference among 4 groups at T2. The MBP of all 4 groups at Ta and Tb were significantly lower than their levels at any other time (P<0.05, Ta and Tb vs other time), but there’s no significant difference among 4 groups at Ta and Tb. At Ta, the SpO2 of GII was significantly lower than GI, GIII and GIV (P<0.05); at Tb, the SpO2 of GII was significantly lower than GI (P<0.05) and GIV (P<0.01); at Tc, the SpO2 of GIII were significantly lower than GIV (P<0.05).Conclusion: Intravenous butorphanol 1 mg could effectively suppress SIC before sufentanil injection. Without waiting time before administering the sufentanil may be feasible in clinical practice, it has the same suppressive effection and has no influence on BP, HR, SpO2 and the total amount of sufentanil. Trial registration: Chinese Clinical Trial Registry with registration number ChiCTR1900024394. Registered 9 July 2019.