To investigate the clinical effect of salvia miltiorrhiza ligustrazine on chronic obstructive pulmonary disease （COPD） complicated with respiratory failure and its effect on pulmonary function, blood gas and inflammatory factors. Methods:Ninety-eight patients with COPD complicated with respiratory failure were selected and randomly divided into a treatment group and a control group, each 49 cases. The control group was treated with conventional western medicine, while the treatment group was treated with salvia miltiorrhiza ligustrazine on the basis of the control group, all treated for 14 d. The clinical efficacy of the 2 groups were evaluated, and the changes of pulmonary function, blood gas and inflammatory factors were detected and compared between the 2 groups. Results:The total effective rate of the treatment group was 97.96%, which was significantly higher than 83.67% of the control group （P<0.05）; After treatment, the FEV1, FVC, FEV1/FVC of 2 groups, PaO2 and SaO2 levels of 2 groups were significantly higher than before treatment （P<0.01）, and the treatment group was significantly higher than that of the control group （P<0.05 or P<0.01）. The level of PaCO2 in 2 groups was significantly lower than that before treatment, and the treatment group was significantly lower than the control group （P<0.01）; after treatment, the levels of serum IL-6, IL-8, CRP and TNF-α in 2 groups were significantly lower than those before treatment （P<0.01）, and the treatment group was significantly lower than those in the control group （P<0.01）. Conclusion:Salvia miltiorrhiza ligustrazine can effectively reduce the levels of inflammatory factors in patients with COPD complicated with respiratory failure, improve the blood gas index, and then promote the recovery of lung function with precise clinic effect.