Ventricular septal defect 3 mm has a certain probability of self-healing, it is recommended to go to the regular hospital for diagnosis and treatment. Ventricular septal defect belongs to a congenital heart disease, if infants and young children are not healed within 6 months after birth, it is difficult to rely solely on drugs or their own healing ability to recover, it is recommended to go to the cardiology department of the regular hospital for diagnosis and treatment in a timely manner. Although the 3mm ventricular septal defect, the scope of the defect is relatively small, the impact on the heart function is not particularly serious, if not healed within 6 months after birth, the doctor will choose the appropriate intervention according to the patient’s specific situation, usually using the appropriate blocking material to plug the gap, the prognosis is good, and the earlier the intervention is performed, the better the recovery of the patient’s cardiac function. It is recommended to consult a doctor in time and standardize the treatment under the doctor’s guidance.