Liver cancer has become a major global health challenge due to its high incidence, high rate of late diagnosis and limited treatment options. Although there are many clinical treatments available for liver cancer, the cure rate is still very low, and now researchers have begun to explore new aspects of liver cancer treatment, and nanotechnology has shown great potential for improving diagnostic accuracy and therapeutic efficacy and is therefore a promising treatment option. In diagnosis, nanomaterials such as gold nanoparticles, magnetic nanoparticles, and silver nanoparticles can realize highly sensitive and specific detection of liver cancer biomarkers, supporting diagnosis and real-time monitoring of the disease process. In terms of treatment, nanocarriers can realize precise targeted delivery of drugs, improve the bioavailability of liver cancer therapeutic drugs and reduce systemic toxic side effects. In addition, advanced technologies such as nanoparticle-based photothermal therapy and photodynamic therapy provide innovative solutions to overcome drug resistance and local tumor ablation. Therefore, in this paper, we will introduce nanotechnology for hepatocellular carcinoma in terms of tumor marker detection, targeted drug delivery, and synergistic PDT/CDT therapy.