Abstract：Objective：To observe the clinical efficacy of Shengmai Yin combined with bacterial lysates capsules in treating stable chronic obstructive pulmonary disease （COPD）. Methods： A total of 102 stable COPD patients treated at Taizhou First People's Hospital from January 2021 to January 2023 were divided into the control group and the combination group according to the random number table method，with 51 cases each. The control group received basic treatment including expectorants and low-flow oxygen therapy， plus oral Bacterial Lysates Capsules； while the combination group received additional Shengmai Yin Oral Liquid. Both groups were treated for three months. Lung function，exercise tolerance，immune indicators，and acute exacerbation risk were compared between the two groups. Results：After treatment，both groups showed decreased residual volume/total lung capacity （RV/TLC） （P＜0.05）， with lower values in the combination group （P＜0.05）. After treatment， maximal mid-expiratory flow （MMEF） and maximum voluntary ventilation percentage predicted （MVV%pred） increased in both groups （P＜0.05）， with higher values in the combination group （P＜0.05）. The 6-minute walking distance （6MWD），anaerobic threshold percentage predicted （AT%pred）， maximal metabolic equivalents （METs）， and peak oxygen uptake （VO2 peak） improved in both groups （P＜0.05）， with greater improvement in the combination group （P＜0.05）. After treatment， Th17 cells decreased while IL-10， CD3+ ， and CD4+ increased in both groups （P＜0.05）， showing better results in the combination group （P＜0.05）. Follow-up revealed fewer moderate/severe exacerbations and hospitalizations in the combination group，the difference being significant （P＜0.05）. Conclusion：Shengmai Yin combined with Bacterial Lysates Capsules effectively treats stable COPD by improving immune function and pulmonary function while reducing acute exacerbation risk.