Objective:To investigate the effect of high-intensity interval training on cognitive weakness in elderly patients with coronary heart disease.Methods:A randomized controlled study was used. A total of 70 elderly patients with coronary heart disease after discharge from the Cardiology Department, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine from June 2020 to June 2021 were selected and divided into the control group (35 cases) and the observation group (35 cases) by random digits table method. The control group received conventional treatment, and the observation group received high-intensity interval training on the basis of conventional treatment. The changes of peak oxygen intake (PeakVO 2), anaerobic threshold oxygen uptake (ATVO 2), Fried phenotype score, Montreal Cognitive Assessment score, and SF-36 quality of life assessment score before and after 12 weeks of intervention were compared between the two groups. Results:During the intervention, 2 cases fell off in the control group and 2 cases in the observation group. After 12 weeks of intervention, PeakVO 2 and ATVO 2 in the observation group were (23.91 ± 5.88), (20.79 ± 5.19) ml·min -1·kg -1, respectively, higher than those in the control group(20.56 ± 5.81), (17.29 ± 5.36) ml·min -1·kg -1, and the differences were statistically significant ( t = 2.38, 2.69, both P<0.05). The scores of SF-36 quality of life assessment and Montreal Cognitive Assessment in the observation group were (85.33 ± 6.43), (22.64 ± 3.81) points, which were significantly higher than those in the control group (78.72 ± 8.14), (20.67 ± 3.04) points, and the differences were statistically significant ( t = 3.66, 2.32, both P<0.05); the Fried phenotype score in the observation group was (1.36 ± 0.99) points, which was significantly lower than that in the control group (3.03 ± 1.08) points, and the difference was statistically significant ( t = 6.54, P<0.05). Conclusions:High-intensity interval training can improve cardiopulmonary function, aerobic exercise ability, cognitive weakness and quality of life in elderly patients with coronary heart disease.