Color Doppler ultrasound uses four-dimensional imaging technology and has powerful four-dimensional ultrasound stereo imaging. It can intuitively and stereoscopically display the three-dimensional structure of human organs and dynamic 4D ultrasound technology. It has powerful stereo imaging, basic imaging, tissue harmonics, image viewing and other functions. It has clear images, good resolution, high diagnostic accuracy, safety and reliability. It can be used to diagnose various difficult diseases such as the abdomen, obstetrics and gynecology, digestive system, urinary system, blood vessels, small organs, etc., especially for the fetus. It can observe the growth and development of the fetus in the uterus from multiple directions and angles, and intuitively display the fetal face, spine, limbs and other structures, so as to provide accurate scientific basis for the early diagnosis of congenital surface malformations of the fetus and improve the diagnosis rate of fetal malformations.