Bufei Yishen Prescription on Patients With Frequent AECOPD in Stable Stage

Inclusion Criteria: * Patients diagnosed with COPD at a stable stage. * Stable COPD patients with frequent acute exacerbation. * Age 40-80 years old. * The condition was stable 4 weeks before enrollment. * 5 did not participate in other drug clinical studies within 1 month before enrollment. * At least 3 months of maintenance therapy with triple inhalation preparation was used before enrollment. * Washout period was 2 weeks before enrollment. * Voluntarily receive treatment and sign informed consent. Exclusion Criteria: * complicity with other diagnosed and clinically significant respiratory diseases, including but not limited to: asthma, active pulmonary tuberculosis, bronchiectasis, pulmonary hypertension, pulmonary embolism, pneumothorax, pleural effusion, interstitial lung disease, or other active pulmonary diseases requiring intervention. * Patients with severe or acute cardiovascular and cerebrovascular diseases (acute cardiovascular and cerebrovascular events, malignant arrhythmias, unstable angina pectoris, cardiac function grade 3 or above, uncontrolled hypertension, etc.). * Complicated with severe liver and kidney disease (severe liver disease refers to cirrhosis, portal hypertension and varicose vein bleeding, serious kidney disease including dialysis, kidney transplantation). * Any item of liver function index (ALT, AST) exceeds the upper limit of normal reference value by 1.5 times, and renal function index Scr exceeds the upper limit of normal reference value. * Tumor patients who have undergone surgical resection, radiotherapy and chemotherapy in the past five years. * Patients with mobility difficulties caused by severe osteoarthropathy, neuromuscular disease, and peripheral vascular disease. * Combined with absolute or relative prohibition of 6-minute walking test: such as resting heart rate \> 120 beats/min, systolic blood pressure \> 180mmHg or diastolic blood pressure \> 100mmHg; Or have limited activity to complete the 6-minute walking test. * Combined with cognitive or mental disorders. * Glucocorticoids were taken orally within 2 weeks before enrollment. * Had taken any Chinese medicine preparations (decoction, formula granule, proprietary Chinese medicine, etc.) prohibited during the study period according to the protocol within 2 weeks before enrollment. * People who are known to be allergic to therapeutic drugs. * Pregnant and lactating women, people who plan to become pregnant or cannot use effective contraceptive measures.