Abstract: The small airways of the lungsare a key lesion site of chronic obstructive pulmonary disease, which has existed before the disease progresses tochronic obstructive pulmonary disease.However, this site is often overlooked due to the lack of clinical symptoms and systematic diagnosis and treatment. In recent years, small airway diseases have attracted more and more attention. Early detection and treatment of small airways are crucial for slowing down the progression of diseases and improving prognosis. This paper reviews the pathology, evaluation and treatment of small airways inchronic obstructive pulmonary disease, providing thoughts for clinical treatment and subsequent research direction.