Pyogenic liver abscess (PLA) accompanied by occult malignant tumors is a rare kind of life-threatening disease. Studies have shown that it can predict the occurrence of cancer, especially hepatobiliary and colorectal cancer. The risk of combined occult primary liver cancer, cholangiocarcinoma, and gastrointestinal cancer is high in PLA patients. Malignant tumor-related PLA lacks specific symptoms and signs. The iodine concentration ratio between the energy spectrum CT lesions and normal liver tissue is of certain value in the differentiation of liver cancer and liver abscess. Computed tomography colonography has a dual role. It can screen patients with PLA for occult colorectal cancer and determine the treatment response of abscess lesions. Klebsiella pneumoniae and Escherichia coli is the main microorganism of PLA related to colorectal cancer, hepatocellular carcinoma, and intrahepatic cholangiocarcinoma. PLA treatment related to hepatobiliary malignant tumor has high complications and mortality, and poor prognosis. Most occult colorectal cancers are in the early stage, and their early detection and prognosis are better than those of PLA patients combined with hepatobiliary malignancies.