〔Abstract〕 Objective To explore the effects of high flow respiratory humidification therapeutic apparatus on pneumonia function, blood gas indexes and clinical efficacy in patients with severe pneumonia. Methods A total of 120 patients with severe pneumonia who were treated in Zhongshan Hospital Affiliated to Xiamen University from January 2020 to May 2022 were randomly divided into an observation group and a control group, with 60 cases in each group. Patients in the two groups for anti-infection treatment. On this basis, the control group was treated with non-invasive mechanical ventilation, and the observation group used high flow respiratory humidification therapeutic apparatus for auxiliary oxygen inhalation, The treatment indicators (serum inflammatory factors, pulmonary ventilation function, arterial blood gas analysis and quality of life) were compared between the two groups before and after treatment, and the total effective rate, symptom relief time and hospitalization time were compared between the two groups. Results The total effective rate of the observation group was higher than that of the control group. Compared with the control group, the relief time of cough, expectoration, shortness of breath and other symptoms in the observation group was shorter, and the length of hospitalization time was shorter. After treatment, the levels of serum inflammatory factors in the observation group were lower than those in the control group. Comparison among groups, the forced expiratory volume in the first second (FEV1), forced expiratory volume in the first second/forced vital capacity ratio (FEV1/FVC), arterial partial pressure of oxygen (PaO2) and oxygenation index in the observation group were higher, while partial pressure of carbon dioxide (PaCO2) in the observation group was lower. After treatment, the quality of life score in the observation group was higher than that in the control group, and the differences were statistically significant (P < 0.05). Conclusion In patients with severe pneumonia, high flow breathing humidification therapeutic instrument can reduce inflammatory response, pulmonary ventilation dysfunction and arterial blood gas disorder, and improve the quality of life.