Objective In this study, we compared the arytenoid elevation angle measured by ultrasound with the grade of laryngeal mask positioning obtained by fiberoptic bronchoscopy (FOB) and explored the feasibility and application value of neck ultrasound instead of FOB to assess the position of pediatric laryngeal mask airway (LMA), and determine the diagnostic value of cervical ultrasound in monitoring LMA rotation or displacement during pediatric LMA ventilation. Methods 160 children under general anesthesia were selected. After clinical assessment of correct placement of LMA, First, fibrobronchoscopy was placed to confirm the laryngeal mask airway position, and cervical ultrasound (USG) was used to observe the angle of asymmetric elevation of the arytenoid cartilage on both sides when the LMA rotated or shifted. The corresponding relationship between the angle and the position grading of the laryngeal mask under fiberoptic bronchoscopy was analyzed, LMA grading under FOB, elevation angle of the arytenoid cartilage on both sides (α),negative clinical test, oropharyngeal leak pressure (OLP),gastrointestinal flatulence during operation, secretions attached after LMA extraction, and postoperative throat pain were recorded. Results The consistency parameter kappa coefficient between the classification of LMA by FOB positioning and the asymmetric elevation angle of arytenoid cartilage on both sides of the rotated or displaced LMA measured by USG was 0.9116. When the laryngeal mask was rotated or shifted, the elevation angle (α) of arytenoid cartilage measured by ultrasound in the central transverse section of the neck was classified as follows: grade 1 (mild rotation): 0°＜α≤10°, grade 2 (moderate rotation) : 10°＜α≤20°, grade 3 (severe rotation) : 20°＜α≤30°, and grade 4 (extremely severe rotation) : α＞ 30°. Among the 160 children, 150 (93.75%) were successfully implanted with AMBU LMA at the first time, and the clinical test negative rate was 93.75%. 10 children (6.25%) needed to be implanted for the second time due to positive clinical test. The proportion of high OLP decreased with the increase of rotation angle classification and the incidence of intraoperative gastrointestinal flatulence, attached secretions after LMA removal and postoperative throat pain were significantly increased (P＜0.05).Conclusion The elevation angle of arytenoid cartilage after LMA placement in children by ultrasound is consistent with the LMA classification by FOB positioning. Clinically, real-time diagnosis of the LMA position by ultrasound could not only make adjustments quickly, but also avoid multiple FOB examinations to aggravate hypoxemia. Moreover, it provides reference for clinical anesthesiologists to judge the position of laryngeal mask airway