Chronic Obstructive Pulmonary Disease (COPD) is a common respiratory disease that seriously endangers the physical and mental health of patients. Standardized treatment for COPD patients can stop the development of the disease, delay the acute exacerbation, improve the quality of life, reduce the rate of disability and death, and reduce the burden of disease. COPD is a preventable and treatable disease characterized by airflow limitation. COPD is a preventable and treatable disease characterized by airflow limitation, which is not fully reversible, progresses progressively, and is associated with an abnormal inflammatory response of the lungs to the inhalation of harmful gases or particles such as tobacco smoke.COPD primarily involves the lungs, but can also cause systemic (or extrapulmonary) adverse effects. Pulmonary function tests are important to clarify the presence of airflow limitation. After inhalation of bronchodilators, if the exertional expiratory volume in one second as a percentage of the exertional lung volume (FEV1/FVC%)