Objective <p>The aim of this study was to probe the clinical effect of a high proportion of cefoperazone/tazobactam in the treatment of patients with chronic obstructive pulmonary disease (COPD) involuted with lower respiratory tract infection <i>Klebsiella pneumoniae.</i></p> Methods <p>80 patients with COPD and lower respiratory tract infection <i>Klebsiella pneumoniae</i> accepted to the Respiratory Department of our hospital from January 2022 to January 2024 were selected as the research subjects. They were randomly divided into a low-proportion group (n = 40) and a high-proportion group (n = 40). Patients in the low-proportion group and the high-proportion group received intravenous infusion of cefoperazone/tazobactam in a proportion of 4: 1 and 8: 1 respectively, and both were treated for one week.</p> Results <p>After one week of treatment, the APACHE Ⅱ scores and dyspnea scores of patients in the high-proportion group and the low-proportion group were significantly lower than those before treatment (<i>P</i> &lt; 0.05), and the low-proportion group was slightly lower than the high-proportion group. After one week of treatment, the serum CRP concentration of patients in the low-proportion group and the high-proportion group was reduced compared with before treatment (<i>P</i> &lt; 0.05), while the lung function FEV1/FVC (%) value was increased compared with before treatment (<i>P</i> &lt; 0.05), and the FEV1/FVC (%) value after treatment was higher in the high-proportion group than in the low-proportion group (<i>P</i> &lt; 0.05).</p> Conclusion <p>In the treatment of COPD patients with lower respiratory tract infection <i>Klebsiella pneumoniae</i>, intravenous infusion of cefoperazone/tazobactam in a proportion of 8: 1 is a better treatment plan. High-proportion intravenous infusion of cefoperazone/tazobactam can quickly restore the patient’s lung function and is more effective in improving treatment efficiency and bacterial clearance rate.</p>