Mitochondria act as the main energy supply station for cardiomyocytes and are thus crucial for maintaining normal cardiac function. Mitochondrial autophagy plays an important positive role in maintaining cardiomyocyte homeostasis and coping with stress. The progressive exacerbation of cardiovascular diseases presents a challenge to the homeostasis of mitochondrial autophagy through as-yet-unidentified pathological mechanisms, leading to mitochondrial damage, which may in turn trigger damage to cardiomyocytes. In addition, when mitochondrial autophagy fails to meet the physiological needs of the body, mitochondrial dysfunction may be triggered, which may in turn accelerate the progression of heart failure. In this review, we explore the specific roles of mitochondrial autophagy and mitochondrial dynamics in the heart, and discuss the mechanisms in the context of major cardiovascular diseases, focusing on the latest advances and important discoveries in this field.