Objective To compare the effects of bispectral index (BIS) monitoring with three different depths of sedation in lucid fiberoptic bronchoscopy. Methods Ninety patients underwent lucid fiberoptic bronchoscopy from July 2017 to January 2018 in Wenzhou Integrated Traditional Chinese and Western Medicine Hospital in Zhejiang Province were selected. The patients were divided into group A, group B and group C according to the random digits table method with 30 cases each. The depth of sedation in group A was set BIS at 65 to 69, in group B BIS at 70 to 74, and in group C BIS at 75 to 79. At the beginning of sedation, propofol and remifentanil were administered continuously intravenously at a target concentration of 1 μg/ml and 3 ng/ml, then 0.25 μg/ml of propofol was adjusted according to the change of BIS. Fiberoptic bronchoscopy was performed after the patient′s BIS reached the pre-set target value. The BIS, heart rate, mean arterial pressure (MAP) and pulse oxygen saturation (SpO2) at admission to the examination room (T0), sedation (T1), fiberoptic bronchoscopy through glottis (T2), fiberoptic bronchoscopy into trachea (T3), 15 min after the examination (T4) were recorded. During fiberoptic bronchoscopy, the numbers of cough accompanied by body movement, additional injection of lidocaine, hypoxemia, assisted ventilation, detection time and degree of patients or doctors satisfaction were recorded. Results The heart rate and MAP at T1 in 3 groups were significantly lower than those at T0, and there were statistical differences (P＜0.05); the heart rate and MAP at T2 and T3 in group C were significantly higher than those at T1 and the same time points in group A and group B, and there were statistical differences (P＜0.05); the SpO2 at T3 in group A was significantly lower than that in group B and group C, and there was statistical difference (P＜0.05). The incidences of cough accompanied by body movement and additional injection of lidocaine in group C were significantly higher than those in group A and group B: 63.3% (19/30) vs. 10.0% (3/30) and 13.3% (4/30), 50.0% (15/30) vs. 6.7% (2/30) and 10.0% (3/30), and there were statistical differences (P＜0.05); the incidence of hypoxemia in group A was significantly higher than that in group B and group C: 63.3% (19/30) vs. 23.3% (7/30) and 6.7% (2/30), group B was significantly higher than group C, and there were statistical differences (P＜0.05); the incidence of assisted ventilation in group A was significantly higher than that in group B and group C:36.7% (11/30) vs. 3.3% (1/30) and 0, there was statistical difference (P＜0.05). The detection time in group B was significantly shorter than that in group A and group C: (17.6 ± 2.8) min vs. (22.6 ± 3.3) and (21.0 ± 2.6) min, the degree of patients satisfaction in group A and group B was significantly higher than that in group C: (95.5 ± 2.6) and (95.2 ± 3.3) scores vs. (79.3 ± 2.9) scores, the degree of doctors satisfaction in group B was significantly higher than that in group A and group C: (95.8 ± 3.3) scores vs. (83.9 ± 4.2) and (81.0 ± 2.6) scores, there were statistical differences (P＜0.05). Conclusions The BIS setting of sedation depth between 70 and 74 during lucid fiberoptic bronchoscopy has more advantages, less adverse reactions, stable hemodynamics, and higher degree of patients and doctors satisfaction.