Obstructive sleep apnea hypoventilation syndrome (OSAHS) is a common and more harmful sleep disordered breathing disorder characterized by frequent sleep apnea and/or hypoventilation, causing nocturnal hypoxemia and hypercarbia. The incidence is very high and is gaining attention both at home and abroad. Therefore, it is necessary to measure the size of the palatopharyngeal cavity and evaluate the efficacy before and after the preservation of the uvula with UPPP plus low-temperature plasma radiofrequency surgery, in order to further explore the influence of the anatomical morphology of the pharyngeal cavity on the efficacy of the surgery, and to formulate a reasonable scope of surgical resection for the clinical treatment of In order to provide theoretical basis and practical experience for the clinical treatment of OSAHS, it is necessary to further investigate the influence of anatomical changes of the pharyngeal cavity on the surgical efficacy and to formulate a reasonable scope of surgical resection. The UPPP group preserved the soft palate with reference to the normal length of the soft palate and partially or completely excised the uvula. No dead space was left in the tonsillar fossa to increase the tension of the lateral pharyngeal wall and to avoid mucosal tears affecting the expansion of the lateral pharyngeal diameter, and the soft palate was treated with low-temperature plasma radiofrequency two weeks after surgery.