Congenital ventricular septal defect is a condition in which the ventricular septum is underdeveloped during embryonic life, forming abnormal traffic and creating a left-to-right shunt at the ventricular level. Ventricular septal defect is a better common congenital heart disease, accounting for about 20% of congenital heart diseases. In small defects, the defect may be asymptomatic. In large defects, symptoms appear early and are so pronounced that they affect development, with symptoms of shortness of breath, dyspnea, excessive sweating, feeding difficulties, malaise and recurrent pulmonary infections, and in severe cases, heart failure and cyanosis may occur in cases of significant pulmonary hypertension. The prognosis is good for those with small ventricular septal defects, with a natural life expectancy of even 70 years or more, and those with small defects may even close on their own before the age of 10. A left-to-right shunt is created at the ventricular level, the amount of which depends on the size of the defect. In large defects, the blood flow in the pulmonary circulation increases significantly and flows back into the left atrium and ventricle, which increases the left heart load and enlarges the left atrium and ventricle. Long-term increased blood flow in the pulmonary circulation leads to increased pulmonary artery pressure and increased systolic load in the right ventricle, which may increase in size and, better yet, eventually enters the phase of obstructive pulmonary hypertension, where bidirectional or right-to-left shunts may occur. The disease predisposes to infective endocarditis. The typical sign is a rough systolic murmur of grade 4 to 5 between ribs III and IV at the left edge of the sternum, which is conducted to the precordial region, accompanied by a fine systolic tremor. If the fractional flow is high, there may be a functional diastolic murmur in the apical region and a hyperactive and split second pulmonary valve sound. In the presence of severe pulmonary hypertension, there is a diastolic murmur of relative pulmonary valve insufficiency in the pulmonary valve region, and the systolic murmur of the original septal defect may be diminished or absent. This disease is a congenital disease, there is no effective preventive measures, early detection, early diagnosis and early treatment should be achieved. Heart failure can occur at the age of 1 to 2 years for large defects, and the prognosis is poor for those with pulmonary hypertension. Timely surgical treatment can generally achieve results that are no different from those of normal people.