Liver ultrasound can be used to check whether the liver is normal in size, echogenicity and structural changes, and color Doppler can be used to further define the shape of blood vessels and blood flow, which can be used to make a preliminary diagnosis of a number of diseases: 1) Diffuse diseases of the liver, such as cirrhosis, fatty liver, hepatic schistosomiasis, etc.; 2) Focal lesions in the liver, such as hepatic cysts, hepatic abscess, hepatic cysts, liver abscesses, liver hemangiomas, primary hepatocellular carcinoma, metastatic hepatocellular carcinoma, etc.; 3. liver trauma; 4. vascular lesions of the liver, such as arteriovenous fistulae; 5. biliary lesions of the liver; 6. perioperative evaluation of liver transplantation. Ultrasonography also has some limitations, some liver lesions through the routine ultrasound examination, it is difficult to clarify the specific nature and type, sometimes need to be further through ultrasonography or other imaging methods for differential diagnosis, and even need to be ultrasound-guided puncture biopsy to be able to clarify.