Ultrasound is a sound wave with a frequency of 20,000 Hz or more than that which can be heard by the normal human ear. Using the physical characteristics of ultrasound and the differences in the acoustic properties of human organs and tissues, it is displayed and recorded in the form of waveforms, curves or images, and the diagnostic method of discriminating physiological and pathological conditions based on the characteristics of the images is ultrasound. Ultrasound diagnosis is non-invasive, convenient and intuitive, so it is very popular among clinicians and patients. It is considered one of the four major diagnostic imaging techniques in modern medicine, along with X-ray, CT, magnetic resonance imaging and isotope. There are many types of ultrasound diagnostics, which can be generally divided into type A, type B, type D, type M and so on. B-type ultrasound is the basis of all ultrasound diagnosis, which can directly display two-dimensional spatial images, so it is also called two-dimensional ultrasound. D-type ultrasound is also called Doppler type, through the blood flow and organ activity of the Doppler frequency shift signal, after autocorrelation technology and other processing, color coding and superimposed on the two-dimensional image of B-type ultrasound, which is generally This is the general sense of color ultrasound. Therefore, color ultrasound can provide both morphological and hemodynamic information in two dimensions, and is the mainstream of ultrasound diagnosis today. In recent years, new technologies such as three-dimensional ultrasound and ultrasonography have emerged, which have greatly enhanced the scope and level of ultrasound diagnosis. Conventional ultrasound examinations are done on the surface of the body. Some organs or lesions are located deep inside the pelvic cavity and other parts of the body, when intracavitary detection methods can be used to avoid the influence of other tissues, such as transesophageal examination of the digestive tract and heart, transrectal examination of the prostate, transvaginal examination of the uterus and adnexa, etc. The correct insertion or injection of puncture needles, drainage catheters or drugs into the lesions, cystic cavities, body cavities, ducts and other specific sites to be reached under ultrasound guidance for diagnostic or/and therapeutic purposes is called interventional ultrasound. In addition, ultrasound can be used to guide the treatment of tumors or directly to treat tumors using high-energy focused ultrasound. Ultrasound technology is used mainly for the diagnosis of fluidic and substantive lesions in the body and is extremely widely used. It is used in the cranial, cardiac, vascular, hepatic, biliary, pancreatic, splenic, thoracic, renal, ureter, bladder, urethra, uterus, pelvic adnexa, prostate, seminal vesicles, and eye, thyroid, breast, salivary gland, testis, peripheral nerves and tendons of the extremities. However, ultrasound diagnosis has some limitations, such as limited diagnostic value for lesions in the stomach, lungs and gastrointestinal tract. Therefore, in clinical use, it is necessary to combine clinical and other diagnostic information to make a comprehensive judgment in order to arrive at a correct diagnosis.