Primary liver cancer seriously threatens human health, affects the quality of life, and has a high mortality rate. Traditional Chinese medicine (TCM) has long been used in the prevention, treatment, and adjuvant treatment of primary liver cancer. Clinical trials were conducted in recent years to evaluate the efficacy and safety of TCM. The mechanism of action of TCM in primary liver cancer treatment also received extensive attention. This study summarizes the common monomial Chinese herbal medicines and their components, formulae, and the proprietary Chinese medicines used to treat primary liver cancer. Common medicines include Chansu (Bufonis venenum), Kushen (Sophorae flavescentis radix), Renshen (Ginseng radix et rhizoma), and Jianghuang (Curcumae longae rhizoma). This study also reviewed the literature on liver cancer treatment using TCM. The results confirmed the safety and efficacy of TCM in liver cancer treatment. The possible mechanisms involved are also listed, including influencing the cell cycle, inducing cancer cell apoptosis and autophagy, inhibiting cancer cell angiogenesis and metastasis, regenerating the microenvironment and DNA methylation, and regulating the innate immune response. For primary liver cancer patients who often have a long disease course, Chinese herbal medicine often plays a role in protecting and conditioning the body. Research aimed at finding more traditional Chinese herbal medicines and their mechanisms of action should be promoted. This study aimed to provide a scientific reference for further research and the rational clinical application of TCM for primary liver cancer treatment.