Objective This study compared the situation of insertion of BlockBuster device, the occurrence ratio and duration of apnea under the general anesthesia induction by sevoflurane‑propofol versus sevoflurane for obese patients undergoing bariatric surgery. Methods Sixty obese patients were randomly (by SPSS software to generate random numbers) assigned into two groups (n=30): sevoflurane (S) group and sevoflurane combined with propofol (SP) group. Propofol 1 mg/kg according to lean body weight was intravenously administered at a constant speed in the SP group, and normal saline was infused at a constant speed in the S group. Then, 5% sevoflurane was continuously inhaled by patients in both groups until loss of consciousness. After loss of consciousness, the inspired concentration of sevoflurane was adjusted to end‑tidal concentration of 3.0% for the S group and 2.7% for the SP group, respectively. Tried inserting the BlockBuster device after jaw relaxation. The insertion condition of BlockBuster device, the respiratory parameters during anesthesia induction [the incidence and duration of apnea, pulse oxygen saturation (SpO2), respiratory rate and tidal volume at 1 min before anesthesia induction (T0), 1 min after anesthesia induction (T1), 1 min before device insertion (T2), and 1 min after device insertion (T3)] were recorded. Results There was no statistically significant difference between the two groups in the rates of successful insertion of BlockBuster device at the first and second attempt, the score of the first laryngeal mask insertion, the number of laryngeal mask insertions and the incidence and duration of apnea (P>0.05). There was also no statistically significant difference in tidal volumes between the two groups at different time points (P>0.05). Compared with the S group, the duration for the procedures of laryngeal mask insertion and anesthesia induction were short in the SP group. The respiratory rates decreased at T2 in the SP group (P<0.05). Compared with T0, the tidal volumes decreased at T1, T2, and T3 (P<0.05), the respiratory rates increased at T2 and T3 (P<0.05) in the S group. However, the respiratory rates of the SP group decreased at T1 and increased at T2 (P<0.05). Compared with T2, the tidal volumes in both groups increased at T3 (P<0.05). There was no cases of SpO2<90%, severe bradycardia (heart rates<45 bpm) and hypotension [SBP<90 mmHg (1 mmHg=0.133 kPa)] in both groups. Conclusions Both sevoflurane alone and sevoflurane combined with propofol can provide adequate insertion conditions for BlockBuster device under spontaneous breathing in obese patients, which are safe and comfortable anesthesia induction methods for obese patients. Compared with sevoflurane alone, sevoflurane combined with propofol is a better choice for anesthesia induction.