During the treatment against tumor, it often causes cardiac function impairment, especially anthracycline chemotherapeutic drugs and monoclonal targeted drugs, which are the most frequent therapeutic drugs causing cardiotoxicity, but these two types of drugs are indispensable in the treatment process of breast cancer, how can we cope with them? The cardiotoxicity of anthracyclines increases with cumulative dose, and the maximum cumulative dose of epoetin is 900-1000 mg/m2. After the application of anthracycline-containing drugs, if the left ventricular ejection fraction (LVEF) decreases to <50%, it needs to be evaluated again after 3 weeks, and if the cardiac function fails to recover, it needs to be considered to discontinue anthracyclines and carry out anti-heart failure treatment, and the follow-up needs to be frequent monitoring of the patient's echocardiography. In patients with severe underlying cardiac disease, anthracyclines often need to be avoided and replaced with other chemotherapeutic agents. Dexrazoxane can be used to reduce the incidence of cardiac events in patients with high risk factors for cardiotoxicity with anthracyclines. Cardiotoxic events induced by the targeted therapy drug trastuzumab, although mostly mild in symptoms, are common in clinical practice, with an incidence of approximately 2.6%-16%. They mainly include asymptomatic reduced left ventricular ejection fraction, tachycardia, chest pain and congestive heart failure. A thorough cardiac evaluation is required prior to the use of trastuzumab, and echocardiography is repeated every three months during the course of use. If LVEF is found to decrease by ≥16% in absolute terms from the pre-treatment value during monitoring, or if LVEF is below the normal range of this monitoring center and LVEF decreases by ≥10% in absolute terms from the pre-treatment value, trastuzumab therapy should be suspended for at least 4 weeks and LVEF should be tested every 4 weeks. Trastuzumab may be resumed, but trastuzumab should be permanently discontinued if LVEF continues to decline for more than 8 weeks or if trastuzumab treatment is interrupted for cardiac problems more than 3 times. All patients should undergo a comprehensive cardiac evaluation before, during, and after treatment, including the performance of ECG, echocardiography, and myocardial enzyme profiles, with an emphasis on prevention and early detection, diagnosis, and treatment. For high-risk groups or patients with underlying cardiac disease, cardiovascular protective drugs can be used as early as possible to minimize damage to the heart.