Objective To explore the application value on patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) of phlegm-dampness internal obstruction type treated by Pinghan Qushi decoction combined with continuous positive airway pressure (CPAP). Methods From December 2021 to December 2023, 122 patients with OSAHS of phlegm dampness internal obstruction type in department of otorhinolaryngology of the hospital were selected and randomized into observation group (62 cases, Pinghan Qushi decoction combined with CPAP) and control group (60 cases, CPAP). The two groups were compared in terms of adverse reactions during treatment and clinical related indexes ［apnea-hypopnea index (AHI), apnea index (AI), hypopnea index (HI)］, TCM syndromes scores, blood routine related indexes ［hemoglobin, red blood cell count (RBC), erythropoietin (EPO)］ and arterial blood gas indexes ［lowest arterial oxygen saturation (LSaO2), PaO2, PaCO2］ before treatment and after 90 days of treatment. ResultsThe clinical related indexes (AHI, AI, HI), TCM syndromes scores, blood routine related indexes and PaCO2 in observation group after 90 days of treatment were significantly lower compared to (AHI, AI, HI, PaCO2) in control group (P＜0.05) while the PaO2 and LSaO2 were significantly higher than control group (P＜0.05). There was no statistical difference in incidence of adverse reactions between groups (P＞0.05). Conclusion CPAP combined with Pinghan Qushi decoction can effectively improve the arterial blood gas and hypoxia status of OSAHS patients with phlegm-dampness internal obstruction, and relieve the clinical symptoms, and it has good clinical efficacy