With the application of 4D ultrasound in clinical practice, the application of 4D ultrasound has become more and more extensive. Because 4D ultrasound is an imaging technology built on the basis of 2D ultrasound, 4D ultrasound can perform whole body organ examination, for example, it can examine the heart, liver, gallbladder, pancreas, spleen, kidney as well as the thyroid, breast, prostate, uterus and ovaries. In addition, in recent years, the application of 4D ultrasound in prenatal examination has become more and more widespread. Through 4D ultrasound, the whole body of the fetus, including the spine, head, face, heart, stomach, liver, kidney, bladder and limbs, can be examined systematically. It can also determine whether the fetus is a singleton or multiple fetus, and understand the growth and development of the fetus, whether there are congenital developmental defects, as well as the size of the fetus, the fetal position, the maturity of the placenta and whether the umbilical cord is wrapped around the neck.