Heart rate variability (HRV) is an important marker of assessing the balance and poor clinical prognosis of the autonomic nervous system (ANS) by detecting HRV. Because it is non-invasive, easy to operate, and the result is accurate and visible. It is widely used in the field of cardiovascular disease. Exercise training is an important part of cardiac rehabilitation. Individualized sports rehabilitation can effectively prevent the emergence of cardiovascular diseases, reduce the risk of recurrent cardiovascular events, and improve not only the dysfunction but also the limited life, work, and social participation caused by adverse cardiovascular events. However, sport is also a double-edged sword, improper training will cause sports injury, excessive fatigue, and even malignant cardiovascular events. This paper reviews the application of HRV in sports rehabilitation for cardiovascular diseases in recent years, providing a reference for the further application of HRV in the field of sports training in cardiac rehabilitation.