Four-dimensional color ultrasound is one of the most important advances in the history of ultrasound medicine. Nowadays, the machines and technology of four-dimensional color ultrasound have become more and more perfect, so it has a wider range of applications in the clinic. In the clinic, four-dimensional color ultrasound can not only be used for pregnant women to carry out prenatal examination, screening the fetus for malformations, but also can be used in other more extensive areas. Because the imaging mode of four-dimensional color ultrasound is more diversified, and its image resolution is higher and clearer, so now four-dimensional color ultrasound can help various clinical disciplines to diagnose diseases, and use four-dimensional modes to display tissues, organs and diseases in a more comprehensive way. At present, the most widely used four-dimensional color ultrasound is the fetal malformation screening in the middle pregnancy. Because the fetus and its appendages in this period of time in the whole pregnancy display the most clear, and four-dimensional color ultrasound of high resolution can clearly show the fetus’s various tissues and organs of the anatomical structure. Therefore, 4D ultrasound examination items are more and more comprehensive than ultrasound examination items in other pregnancy periods. Moreover, when the fetus has malformation or other abnormalities, 4D ultrasound can use 4D 4D 4D 4D mode to reproduce the lesions in three dimensions, which can help ultrasonographers to diagnose the disease more comprehensively. Therefore, many obstetric ultrasonographers say, “Fetal four-dimensional ultrasound screening should be done as much as possible if there are conditions, and if there are no conditions, we should also create the conditions to do it.”