Recently, parents often ask whether echocardiography is harmful to the fetus. Will the heat emitted by the ultrasound probe affect the growth of the fetus? Currently, there are no known adverse effects of echocardiography on the fetus at the international level. The detailed examination of fetal cardiac problems is the same as taking medication for adults, and the patient can benefit most from accurate diagnosis and proper perinatal management. Fetal hearts are very small and technically difficult to diagnose and treat. Fetal cardiac ultrasound is the only effective diagnostic modality in prenatal diagnosis, which is positive for eugenic choices and timely fetal assistance after birth. Taking fetal congenital pulmonary atresia as an example, echocardiography can diagnose the disease and guide the clinic to give a perinatal management plan. If the fetus is judged to be viable in utero, the pregnant woman needs to continue the pregnancy with echocardiographic follow-up evaluations every 3-4 weeks, as well as non-invasive DNA and amniocentesis in conjunction with the specific gestational week. If the pregnant woman terminates the pregnancy, it needs to be done before 28 weeks and preconception testing is recommended for the next pregnancy. Amniocentesis is done between 16-22 weeks of gestation, fetal echocardiography is done between 20-22 weeks, oral folic acid is fortified, and obstetric advice is followed. Before the birth of the fetus, it is necessary to find a hospital with a neonatal care unit and cardiac surgery for delivery, and immediately after birth, prostaglandins are applied to keep the arterial duct open. Afterwards, a surgical plan is developed for treatment based on the results of imaging, echocardiography and other ancillary tests. With the full liberalization of the two-child policy, a wave of births will be ushered in, for which a large wave of elderly pregnant women, the probability of fetal heart disease in pregnancy is twice as high as that of ordinary pregnant women, so it is very necessary to increase the ultrasound examination of the fetal heart.