〔Abstract〕 Objective To investigate the effect of Mahuang Fuzi Xixin Decoction on ACT score and lung function in elderly patients with bronchial asthma. Methods A total of 80 cases of elderly bronchial asthma patients with cold-asthma syndrome admitted to our hospital from April 2018 to September 2019 were randomly divided into two groups for research, a control group and a test group, with 40 cases in each group. The control group was treated with budesonide aerosol. The experimental group was treated with Mahuang Fuzi Xixin Decoction on the basis of the control group. The clinical efficacy, ACT (Asthma Control Test Form) score and lung function index levels of the two groups were compared. Results After treatment, the total effective rate of the observation group was 95.00%, which was significantly higher than the control group's 80.00%, the difference was statistically significant (P < 0.05); the ACT score of the observation group after treatment was significantly higher than that of the control group. The observation group's 1 s forced expiratory volume (FEV1), forced vital capacity (FVC), 1 s forced expiratory volume occupied force vital capacity ratio (FEV1/FVC), maximum expiratory flow (PEF) level was higher than the control group, the difference was statistically significant (P < 0.05). Conclusion Elderly patients with bronchial asthma with cold syndrome should be treated with Mahuang Fuzi Xixin Decoction, which can effectively control asthma symptoms, improve lung function, and have a significant effect.