Chronic obstructive pulmonary disease (COPD) is one of the most common respiratory diseases, clinically characterized by persistent airflow limitation and chronic respiratory symptoms such as dyspnea, cough, and sputum production. Currently, COPD has become the third leading cause of death worldwide, exhibiting high prevalence, high mortality, and a significant disease burden, making its prevention and control a critical public health challenge. The concept of the "gut-lung axis" provides novel insights into the pathogenesis of COPD, as well as its clinical prevention and treatment. The gut microbiota refers to the collective microorganisms residing in the intestinal tract, which play a vital role in maintaining host immunity and metabolic homeostasis. Recent studies have demonstrated the essential role of the gut microbiota in COPD pathogenesis. On one hand, the composition and functionality of the gut microbiota are perturbed in patients and rodents with COPD. On the other hand, gut microbiota derived from COPD patients can induce similar symptoms to those of the disease, whereas restoring the gut microbiota can at least partially delay the progression of COPD and alleviate its symptoms. This review summarizes the latest findings regarding the gut microbiota in COPD, particularly the role of gut microbiota in COPD pathogenesis and its underlying mechanisms, providing new insights into the future investigations, diagnosis and treatment of COPD.