·Forty-five obese patients from Ruijin Hospital, Shanghai Jiao Tong University School of Medicine requiring oral tracheal intubation under general anesthesia were selected and divided into three groups randomly from January to May in 2020: the UE visual laryngoscope intubation group (group A), the Seeing Optical Stylet intubation group (group B) and UE visual laryngoscope combined with Seeing Optical Stylet intubation group (group C), with 15 cases in each. General characteristics, Mallampati classification, tracheal intubation time, and one time success rate of tracheal intubation were documented. Also, mean arterial pressure (MAP) and heart rate (HR) were recorded at different time points, including before anesthesia induction (T1) and 1 (T2), 3 (T3), 5 (T4) and 10 (T5) minutes after tracheal intubation. On the second day after surgery, the intubation complications like coughing, hoarseness, sore throat and tissue damage were observed.

·There were no significant differences in general features among the three groups. Group C has the shortest tracheal intubation time (P=0.007, P=0.001). The fluctuation of MAP (P=0.006, P=0.031) and HR (P=0.013，P=0.042) at T2 in goup C were significantly shorter than the other two groups. Moreover, the incidence of sore throat decreased remarkably in group C compared with group B (P=0.010).

·UE visual laryngoscope combined with Seeing Optical Stylet is recommended in tracheal intubation for obese patients under general anesthesia, which has an advantage of rapid intubation, stable haemodynamics during intubation and fewer complications.