Abstract: Primary liver cancer is one of the most common malignancies and is associated with a high incidence of morbidity and mortality. The intestinal flora plays an important role in the progression of primary liver cancer through the LPS-TLR4 pathways. Moreover, a multitude of factors, such as hepatitis B virus infection, obesity, and an imbalance of intestinal flora, can predispose an individual to the development of primary liver cancer as these factors are interrelated and mutually synergistic. In essence, probiotics are living microorganisms that can exert beneficial effects in the host. This study revealed that probiotics play a positive role against the development of viral hepatitis and cirrhosis and foster the improvement of innate immunity. They were also found to reduce the carcinogenicity of aflatoxins. Furthermore, probiotics can inhibit the advancement of primary liver cancer by stimulating the secretion of anti-inflammatory substances, reducing the number of Th17 cells in tumors, and enhancing antitumor immune responses. This review is focus on the research progress on the correlation between intestinal flora and primary liver cancer.