Primary liver cancer is one of the most common malignant tumors in China, and about 110,000 people die from liver cancer every year, accounting for about 45% of liver cancer deaths worldwide. According to the epidemiological survey of malignant tumors in China, in addition to the high number of middle-aged male liver cancer patients, the number of teenage liver cancer cases is increasing year by year. Patients with early stage liver cancer usually have no conscious symptoms, but once symptoms appear, they are often in the middle to late stage, and the average survival time after diagnosis is 3-6 months, which is known as “the king of cancer”. How to detect liver cancer at an early stage? The most important thing is to enhance the health education of chronic hepatitis and cirrhosis patients about liver cancer disease, raise the awareness of regular follow-up examinations, and conduct regular tumor screening for high-risk groups, so as to greatly improve the chance of early detection of intrahepatic occupancy. Even some patients have timely detected microscopic liver cancer below 2cm through regular monitoring. For the screening of liver cancer, currently accepted screening indicators include: serum alpha-fetoprotein (AFP) and liver ultrasound. AFP is an embryonic antigen produced by immunoassay, which is one of the most specific methods for diagnosing hepatocellular carcinoma and is relatively specific for diagnosing hepatocellular liver cancer. Ultrasonography can reveal the size, shape, location of tumor and the presence of cancer thrombus in the hepatic vein or portal vein, etc. Its diagnostic compliance rate can reach 84% and can detect occupying lesions with a diameter of 2 cm, which is a good non-invasive examination method with localization value. Experts recommend that for AFP >400 μg/L without liver occupancy on ultrasound, attention should be paid to exclude pregnancy, active liver disease and tumors of embryonic origin in the gonads; if not, abdominal enhancement CT and/or magnetic resonance imaging (MRI) should be performed. If AFP appears elevated but does not reach the diagnostic level, in addition to the above-mentioned conditions that may cause increased AFP should be ruled out, the dynamic changes in AFP should be closely tracked, the interval between ultrasound examinations should be shortened to 1 to 2 months, and CT and/or MRI examinations should be performed when needed. If liver cancer is highly suspected, digital subtraction angiography (DSA) hepatic artery iodine oil angiography is recommended. With the progress of medicine, early diagnosis of liver cancer is no longer a medical challenge, and the possibility of early diagnosis of liver cancer can be greatly improved by regular screening of high-risk groups. Early diagnosis is for early treatment, and for high-risk groups such as chronic hepatitis and cirrhosis, it is especially important to raise awareness of regular testing. If one neglects to seek medical treatment because of no conscious symptoms, it is likely to become a major hidden danger in the future.