OBJECTIVE： To observe the clinical efficacy and safety of noninvasive mechanical ventilation combined with aerosol inhalation drug in the treatment of AECOPD complicating with respiratory failure. METHODS： 90 patients diagnosed as AECOPD complicating with respiratory failure were selected and randomly divided into observation group and control group， with 45 cases in each group. Both groups received routine treatment as oxygen supply at low flow rate， anti-infection， relieving asthma， ventilation， cardiotonic， spasmolysis and nutritional support. Control group received noninvasive mechanical ventilation； observation group was additionally given aerosol inhalation of Budesonide atomized liquid+terbutaline+ipratropium bromide， bid. Both groups received 7 d of treatment. Clinical efficacy of 2 groups were compared as well as pH value， PaCO2， PaO2， HR， RR and PEF levels before and after treatment. The occurrence of ADR was observed. RESULTS： Total effective rate of observation group was 93.3％， which was significantly higher than 73.3％ of control group， with statistical significance （P＜0.05）. There was no statistical significance in blood gas analysis indexes， HR， RR and REF between 2 groups before treatment （P＞0.05）. pH value， PaO2 and PEF of 2 groups increased after treatment， while PaO2， HR and RR decreased； the observation group was better than the control group， with statistical significance （P＜0.05）. No obvious ADR was found in 2 groups.  CONCLUSIONS： Noninvasive mechanical ventilation combined with aerosol inhalation drug is effective in the treatment of AECOPD complicating with respiratory failure， and can effectively improve blood gas indexes， HR， RR and PEF with good safety.