The diagnosis of common precordial disease can usually be made based on history, signs, chest x-ray and electrocardiography. M-mode, 2D Doppler and transesophageal echocardiography, especially Doppler color flow imaging and dynamic 3D imaging, as well as computerized magnetic resonance and X-ray tomography, are currently considered to be noninvasive tests of great diagnostic value for this disease. In the medical history, attention should be paid to the age of onset of the heart disease and when the characteristic heart murmur was detected; the younger the age of onset and the detection of the characteristic heart murmur, the greater the likelihood of precordial disease. Family history, prenatal maternal health status and the condition of the child at birth are all informative for diagnosis. In addition, patients with a history of infective endocarditis should be examined for the presence of precordial disease. The presence of hemoptysis in patients with precordial disease is commonly diagnostic because of pulmonary congestion due to massive left-to-right shunts or left heart failure due to aortic and left heart lesions; in addition, hemoptysis can also occur in the pulmonary ischemic type of precordial disease (e.g., pulmonary valve stenosis, tetralogy of Fallot, etc.) due to abundant collateral circulation in the hypoxic lungs. The age at which cyanosis appears is helpful in identifying several right-to-left shunt precordial diseases, such as tetralogy of Fallot, permanent arterial stem, and complete macrovascular misalignment, which have cyanosis since childhood; and Eisenmenger syndrome, which has a late appearance of cyanosis (no cyanosis originally). The occurrence of right heart failure alone without the manifestation of antecedent left heart failure is common in precordial disease with pulmonary hypertension and right heart valve pathology, which is rare in other heart diseases (except for pulmonary heart disease). The most diagnostic value of the signs is the specific murmurs and other heart sound changes that are inherent to the different categories of precordial disease. If this murmur is detected in infancy, the possibility of precordial disease is very high; cyanosis with pestle-like fingers (toes) suggests that cyanosis has existed for many years; an enlarged heart with an elevated precordial area often suggests that the patient has an enlarged heart since childhood, and the possibility of precordial disease is also high. Chest X-ray examination, can understand the change of heart shadow shape, cardiothoracic ratio, the amount of pulmonary blood and observation of the special pulsation of the heart, large blood vessels, etc., can provide information for the diagnosis and differential diagnosis of precordial disease. The electrocardiogram can indicate whether the atria are enlarged, reflect the hemodynamic changes of the lesion to a certain extent, and also find out whether there are arrhythmia conditions. However, it is important to note that different precordial diseases can cause similar radiographic and ECG changes due to the production of similar hemodynamic changes. Cardiac catheterization, combined with selective indicator dilution curve measurement and selective cardiovascular imaging, can provide a more direct understanding of the pathophysiological and pathological anatomical changes in patients with precordial disease by measuring the pressure in each heart chamber and analyzing the oxygen content of blood specimens, injecting the indicator into each heart chamber to observe its dilution, and injecting the contrast agent to observe the flow of the contrast agent and the filling of the cardiovascular chambers. It has the value of confirming the diagnosis and identifying different types of precardiac disease, especially the measurement of pulmonary artery pressure, which is an important reference value for deciding whether there is an indication for surgery and which type of surgery to perform. M-mode echocardiography and two-dimensional echocardiography recorded by sector scanning method, especially transesophageal, can explore the anatomy and physiological activity of the heart, which is sufficient to reflect the anatomical lesions of different types of precardial disease and is a better non-invasive diagnostic method. Computerized magnetic resonance imaging and X-ray tomography can also be used to create three-dimensional reconstruction of the heart from the base to the apex of the multi-level cross-sectional and sagittal images, which can help to understand the anatomical and physiological changes of complex precordial disease, among which magnetic resonance tomography is better than X-ray tomography for soft tissue. Nuclear medicine examination, with the continuous improvement of γ camera and computer processing system, radionuclide examination can provide morphological, hemodynamic and cardiac function information for the function of large blood vessels and lesions of the heart, which is a powerful auxiliary means for the diagnosis of precordial disease. According to the need for surgical treatment, the diagnosis of precardiac disease now requires not only the diagnosis of the nature of the lesion and its location, but also the necessary clinical information on the extent and degree of the lesion. With the development of pediatric cardiology and molecular biology research, it is possible to diagnose and treat precocious heart disease at the embryonic developmental stage in the future.