To observe the effect of Xiaoqinglong decoction combined with noninvasive ventilation on procalcitonin (PCT), blood gas analysis and respiratory functions in acute exacerbation of chronic obstructive pulmonary disease in the elderly (AECOPD), and investigate its correlation and clinical significance. Eighty-four elderly AECOPD patients with respiratory failure in our hospital from January 2015 to October 2017, were randomly divided into control group and observation group, 42 cases in each group. The control group received western medicine combined with noninvasive ventilator therapy, and the patients in observation group additionally received Xiaoqinglong decoction on the basis of the treatment in control group. Both groups were treated for 2 weeks. The clinical effects of two groups were observed and their PCT, blood gas analysis outcomes [arterial oxygen partial pressure (PaO₂), arterial partial pressure of carbon dioxide (PaCO₂), respiratory function, forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV1/FVC], TCM syndrome score and other indexes and adverse reactions were compared before and after treatment. The total efficiency was 95.24% (40/42) in observation group, higher than 76.19% (32/42) in control group, with statistically significant difference (P<0.05). There were no statistically significant differences in PCT, PaO₂, PaCO₂, FVC, FEV1/FVC, FEV1, and TCM syndrome scores between two groups before treatment. But after treatment, PCT and PaCO₂ levels in the observation group were lower and PaO₂, FVC, FEV1/FVC, FEV1 levels was higher than those in the control group (P<0.05); TCM syndrome scores were lower than those in the control group (P<0.05); both groups had no obvious adverse reactions. The results showed that Xiaoqinglong decoction combined with noninvasive ventilator could significantly reduce the procalcitonin level, effectively improve the respiratory function and blood gas analysis indexes, and significantly reduce the clinical symptoms in AECOPD patients, so it is worthy of promotion.