Objective To observe the anesthesia effect and safety of different doses of midazolam on operation in patients with lung cancer , to explore the appropriate dose.Methods 60 cases with lung cancer were divided into observation group and control group according to the dosage of midazolam,30 cases in each group.Hemodynamic changes, recovery time, extubation time, pain score and the dosage of anesthetic drug in the two groups were observed.Results There was no significant differences in hemodynamic indexes of each time point of the two groups .Compared with control group, recovery time, extubation time, pain score, the dosage of propofol and remifentanil dosage in the observation group were significantly lower than that of the control group, the difference was statistically significant (P <0.05).Conclusion Select the 0.075 mg/kg midazolam for lung cancer operation before anesthesia induction can reduce the operation to patients stimulation, make the operation smoothly.