Objective To compare the changes of the upper airway morphology， hyoid bone position， and craniofacial structure before and after extraction treatment and non-extraction treatment in the adult patients with skeletal class Ⅱ high angle malocclusion，and to analyze the effect of extraction orthodontic treatment on the upper airway structure in these patients，and to provide the theoretical basis for the selection of clinical treatment plans. Methods A retrospective analysis on the clinical data of 60 adult patients with skeletal class Ⅱ high angle malocclusion who required orthodontic treatment was collected from the Orthodontics Department of Stomatology Hospital of Jilin University. The patients were divided into extraction group and non-extraction group according to whether treated with extraction orthodontic treatment， and there were 30 patients in each group.The lateral cephalometric radiographs of the patients before and after orthodontic treatment were obtained， and the upper airway， hyoid bone， and craniofacial tissues were delineated and detected by Dolphin software. SPSS 23.0 statistical software was used to perform the statistical analysis on the related measurement data. Results Compared with before orthodontic treatment， the distance between the uvula tip and midpharyngeal wall （U-MPW）， aryngeal wall （V-LPW）， the inner downward angle between the long axis of the upper central incisor and the anterior cranial base （U1-SN） as well as the inner upward angle between the lower central incisor long axis and mandibular plane （L1-MP）of the patients in extraction group with skeletal class Ⅱ high angle malocclusion after orthodontic treatment were significantly decreased（P<0.05），while the occlusal plane and the anterior cranial base （OP-SN） and the angle between the long axes of the upper and lower central incisors （U1-L1） were significantly increased （P<0.05）.There were no significant differences in the other measurement indicators of the patients between two groups （P>0.05）.Compared with before orthodontic treatment， the angle of posterior nasal spine （ANB） of the patients in non-extraction group with skeletal class Ⅱ high angle malocclusion after orthodontic treatment was significantly decreased （P<0.05）， and the OP-SN and L1-MP significantly were increased （P<0.05）. There were no significant differences in the other measurement indicators of the patients between two groups （P>0.05）. Conclusion The sagittal diameter of upper airway of the adult patients with skeletal class Ⅱ high angle malocclusion tended to be orthodontic treatment after extraction orthodontic treatment，mainly in the oropharynx and laryngopharynx of the upper airway， while the hyoid bone position did not change significantly.