〔Abstract〕 Objective To study the effects of rehabilitation training on cardiopulmonary function in elderly patients with coronary heart disease at different periods after discharge. Methods A total of 94 elderly patients with CORONARY heart disease (CHD) admitted to Nanyang Second People's Hospital from August 2018 to December 2019 were randomly selected as the study subjects. According to the different stages of their condition after discharge, they were divided into the stable group (2 weeks to 3 months after discharge, 52 cases) and the early group (2 weeks after discharge, 42 cases). All patients were given rehabilitation training intervention. The improvement of cardiopulmonary function was evaluated and compared between the two groups. Results After intervention, the left ventricular ejection fraction (LVEF), the left ventricular end diastolic diameter (LVEDD), the ratio of peak A and peak E flow rate (E/A), and the peak oxygen uptake (VO2 -- PEAK) of 2 groups were significantly improved, and the walking distance 6 min after intervention was increased compared with that before intervention, with statistical significance (P < 0.05). After intervention, LVEF, E/A, LVEDD, VO2 -- PEAK and 6 min walking distance in stable group were all better than those in early group, with statistical significance (P < 0.05). Conclusion Rehabilitation training for patients with coronary heart disease after discharge from the hospital is of great significance to promote the recovery of their cardiopulmonary function, and the effect of rehabilitation training in the stable period of patients is better than that in the early discharge period, which is more conducive to improving the quality of life of patients and prolonging their life cycle.