Liver cancer is divided into primary liver cancer and secondary liver cancer. Primary liver cancer is more common in China, which is a malignant tumor originating from the liver, and secondary liver cancer is also very common. Secondary liver cancer is a tumor formed when malignant tumors from other parts of the body metastasize to the liver. The primary tumors are mainly colon, rectum, gastric cancer, pancreatic cancer, gastric and intestinal smooth muscle sarcoma, etc. Liver metastasis can also occur in lung cancer, breast cancer, kidney cancer, cervical cancer, ovarian cancer, prostate cancer and head and neck tumors. The occurrence of primary hepatocellular carcinoma is influenced by multiple factors, and the incidence varies in different regions. Currently, it is believed that the development of liver cancer is related to cirrhosis, viral hepatitis, aflatoxin, and certain chemical carcinogens and soil and water factors. Among the known hepatitis viruses, all are associated with liver cancer except hepatitis A and E viruses. And any that can cause extensive inflammation and damage to the liver may cause a series of changes in the liver and eventually lead to the development of liver cancer. It has also been shown that obesity, type 2 diabetes and nonalcoholic steatohepatitis, which lead to fatty infiltration of the liver and consequently nonalcoholic steatohepatitis, are also associated with the development of liver cancer. Therefore, it is important to pay attention to the amount of alcohol consumed in daily life and try to avoid drinking large amounts of alcohol daily. It is also necessary to strengthen nutrition and pay attention to protein and vitamin, especially vitamin B supplementation, in order to improve one’s immunity and prevent the occurrence of liver cancer.