The incidence of nonalcoholic fatty liver disease (NAFLD), a common chronic liver disease, is increasing yearly. With increasing degrees of liver steatosis, NAFLD can progress to varying degrees of hepatic fibrosis, cirrhosis, and even hepatocellular carcinoma (HCC), with a concomitant increase in the risk of metabolic syndrome and cardiovascular disease. Therefore, early diagnosis and accurate assessment of NAFLD are particularly significant. Although liver biopsy is regarded as the standard for evaluating the degree of hepatic steatosis in NAFLD, it is not frequently utilized due to its invasiveness. Ultrasound technology as a noninvasive diagnostic method has the advantages of operating simplicity and economy. It can effectively diagnose and assess the disease of NAFLD. This article mainly summarizes the current status and progress of research on the assessment of NAFLD and liver steatosis by two main types of ultrasound techniques, semi-quantitative and quantitative ultrasound, as well as other emerging techniques, and briefly describes the strengths and limitations of B-mode ultrasound, controlled attenuation parameters (CAP), and attenuation imaging (ATI) in this field.