〔Abstract〕 Objective To analyze the application effect of early continuous positive airway pressure (CPAP) in the prognosis of children with severe pneumonia complicated with respiratory failure. Methods A total of 80 children with severe pneumonia complicated with respiratory failure admitted to Putian First Hospital from January 2020 to June 2022 were selected and divided into groups by random number table method, with 40 cases in each group. The control group was treated with conventional treatment (nasal catheter oxygen inhalation), while the observation group was treated with early continuous positive airway pressure (CPAP). The clinical efficacy of the two groups was compared. Results Lung rale, cyanosis, dyspnea, heart rate recovery to normal and hospital stay in the observation group were shorter than those in the control group, and the differences were statistically significant (P < 0.05). After treatment, the arterial partial pressure of oxygen (PaO2) and pondus hydrogenii (pH) in the observation group were higher than those in the control group, and the arterial partial pressure of carbon dioxide (PaCO2) was lower than that in the control group, and the differences were statistically significant (P < 0.05). There was no significant difference in the incidence of complications between the two groups (P > 0.05). The mortality of the observation group was lower than that of the control group, and the difference was statistically significant (P < 0.05). Conclusion Continuous positive airway pressure (CPAP) in the early stage of severe pneumonia complicated with respiratory failure can effectively improve the blood gas related indicators and prognosis of children and reduce the risk of death.