Abstract: Objective:To investigate the role of non-invasive bi-level positive airway pressure mechanical ventilation(BiPAP) in treatment of hypoxia and hypercapnia in the clinical application.Methods:Sixty-two patients complicated with hypoxia and hypercapnia including chronic obstructive pulmonary disease(COPD) and obstructive sleep apnea hypopnea syndrome(OSAHS) were selected and divided into group A and group B.Thirty-two patients in group A were underwent non-invasive BiPAP mechanical ventilation,others in group B were treated with respiratory stimulant.Heart rate,respiratory rate and blood gas analysis were observed.Results:The symptom of patients in group A with hypoxia and hypercapnia had been improved by non-invasive BiPAP mechanical ventilation.Only 1 patient needed invasive mechanical ventilation by endotracheal intubation.While in group B,4 patients required endotracheal intubation and invasive mechanical ventilation,1 patient was dead because of multiple organ failure.After treatment,the improvement of heart rate,respiratory rate and blood gas analysis in group A were better than in group B(P0.05).Conclusions:Non-invasive BiPAP mechanical ventilation can improve hypoxia and hypercapnia,decrease heart rate and respiratory rate,which plays a good therapeutic effect.BiPAP is a simple,effective,safe,reliable way,and susceptible to remission of disease.