Objective To investigate the effect of cardiac rehabilitation exercise on cardiac function and adverse cardiovascular events in patients with chronic heart failure. Methods A total of 80 patients with chronic heart failure who were admitted to our hospital from January 2020 to April 2021 were enrolled and divided into observation group and control group by the simple randomization method. The patients in the control group were given conventional Western medicine treatment, and those in the observation group were given conventional Western medicine treatment combined with cardiac rehabilitation exercise. The two groups were compared in terms of the improvement in cardiac function and the incidence rate of adverse cardiovascular events. Results Compared with the control group, the observation group had significantly higher left ventricular ejection fraction, cardiac output, and stroke volume and significantly lower left ventricular end-diastolic diameter and left ventricular end-systolic diameter (P<0.05). The observation group had a significantly lower incidence rate of adverse cardiovascular events than the control group (P<0.05). Conclusion For patients with chronic heart failure, cardiac rehabilitation exercise can promote the improvement in cardiac function and reduce the risk of adverse cardiovascular events.