Oxygen therapy is the first-line treatment strategy for acute respiratory failure. Non-invasive oxygen therapy includes non-invasive positive pressure ventilation (NPPV), standard oxygen (oxygen inhalation through nasal cannula), and high-flow nasal cannula (HFNC) humidified oxygen therapy. HFNC is a new type of assisted breathing and has been rapidly popularized in clinical practice in recent years. However, HFNC is a new respiratory support technique, but how to standardize its use in clinical practice and to clarify its applicable scope still needs further clinical research. In order to better save patients′ lives and actively promote patients′ early recovery, this paper clarifies the therapeutic advantages of HFNC by comparing its efficacy with that of standard oxygen and NPPV.