Ultrasound is not a color ultrasound, but a kind of real-time grayscale imaging, which mostly adopts the grayscale modulation display method. This imaging method encodes the grayscale of different levels of tissue echo signal strength in a certain plane, and then displays it on the fluorescent screen dynamically in real time. Ultrasound is a kind of Doppler imaging, which can display the direction of blood flow, blood flow speed and other related information. At present, the clinical use is generally color Doppler imaging, and the multifunctional instrument will generally have a variety of components such as color Doppler M-formation imaging, implementation of grayscale imaging and spectroscopy, etc., which can jointly participate in the formation of the image required for diagnosis and display on the fluoroscopic screen, belonging to a multifunctional instrument.