Hepatocellular carcinoma (HCC) is a significant health concern globally, with limited therapeutic options and poor prognosis. Recent advancements in immunotherapy, particularly immune checkpoint inhibitors (ICIs), have shown promising results in the systemic treatment of HCC. The combination of ICIs with other treatments, such as anti-angiogenic agents and tyrosine kinase inhibitors (TKIs), has become a major trend. Dual immune checkpoint blockade with durvalumab plus tremelimumab has also emerged as an effective treatment for advanced HCC. However, most HCC patients still obtain limited benefits from these therapies. Understanding the immunological rationale and exploring novel strategies to enhance the efficacy of immunotherapy is crucial. This review summarizes the latest progress in understanding the immunosuppressive characteristics of the tumor microenvironment (TME) and the established immunotherapy strategies, including ICIs. It also discusses emerging immunotherapy strategies such as chimeric antigen receptor T cells, personalized neoantigen vaccines, oncolytic viruses, and bispecific antibodies. The review highlights the role of various immune cell types, including tumor-associated macrophages (TAMs), tumor-associated neutrophils (TANs), dendritic cells (DCs), innate lymphoid cells (ILCs), T cells, B cells, and non-hematopoietic stromal cells, in the TME and their impact on HCC progression and immunotherapy response. The heterogeneity of the TME in HCC makes it challenging to predict prognosis and guide clinical treatment. Multi-omics technologies and clinical prognosis integration have been used to classify HCC based on immunology, identifying subtypes such as immune-activated, immune-exhausted, and immunosuppressive. These subtypes provide valuable insights into treatment strategies but require further validation in clinical cohorts. Clinically established immunotherapies, including ICIs and their combinations, have shown encouraging results. The combination of ICIs with anti-VEGF agents and TKIs has demonstrated improved outcomes in phase III trials. The combination of dual PD-1 and CTLA-4 blockades, as well as the combination of PD-L1 antibody durvalumab with CTLA-4 antibody tremelimumab, have been approved by the FDA for the treatment of advanced HCC. The perioperative treatment, including adjuvant therapy, neoadjuvant therapy, and downstaging conversion therapy, has also seen significant advancements with immunotherapies. Phase III studies are ongoing to evaluate the efficacy of ICIs in adjuvant therapy, neoadjuvant therapy, and downstaging conversion therapy. To enhance the response of HCC to ICIs, efforts are being made to identify predictive biomarkers and remodel the TME. The combination of IFN-α and PD-1 blockade is a promising strategy to improve the efficacy of immunotherapy in HCC.Hepatocellular carcinoma (HCC) is a significant health concern globally, with limited therapeutic options and poor prognosis. Recent advancements in immunotherapy, particularly immune checkpoint inhibitors (ICIs), have shown promising results in the systemic treatment of HCC. The combination of ICIs with other treatments, such as anti-angiogenic agents and tyrosine kinase inhibitors (TKIs), has become a major trend. Dual immune checkpoint blockade with durvalumab plus tremelimumab has also emerged as an effective treatment for advanced HCC. However, most HCC patients still obtain limited benefits from these therapies. Understanding the immunological rationale and exploring novel strategies to enhance the efficacy of immunotherapy is crucial. This review summarizes the latest progress in understanding the immunosuppressive characteristics of the tumor microenvironment (TME) and the established immunotherapy strategies, including ICIs. It also discusses emerging immunotherapy strategies such as chimeric antigen receptor T cells, personalized neoantigen vaccines, oncolytic viruses, and bispecific antibodies. The review highlights the role of various immune cell types, including tumor-associated macrophages (TAMs), tumor-associated neutrophils (TANs), dendritic cells (DCs), innate lymphoid cells (ILCs), T cells, B cells, and non-hematopoietic stromal cells, in the TME and their impact on HCC progression and immunotherapy response. The heterogeneity of the TME in HCC makes it challenging to predict prognosis and guide clinical treatment. Multi-omics technologies and clinical prognosis integration have been used to classify HCC based on immunology, identifying subtypes such as immune-activated, immune-exhausted, and immunosuppressive. These subtypes provide valuable insights into treatment strategies but require further validation in clinical cohorts. Clinically established immunotherapies, including ICIs and their combinations, have shown encouraging results. The combination of ICIs with anti-VEGF agents and TKIs has demonstrated improved outcomes in phase III trials. The combination of dual PD-1 and CTLA-4 blockades, as well as the combination of PD-L1 antibody durvalumab with CTLA-4 antibody tremelimumab, have been approved by the FDA for the treatment of advanced HCC. The perioperative treatment, including adjuvant therapy, neoadjuvant therapy, and downstaging conversion therapy, has also seen significant advancements with immunotherapies. Phase III studies are ongoing to evaluate the efficacy of ICIs in adjuvant therapy, neoadjuvant therapy, and downstaging conversion therapy. To enhance the response of HCC to ICIs, efforts are being made to identify predictive biomarkers and remodel the TME. The combination of IFN-α and PD-1 blockade is a promising strategy to improve the efficacy of immunotherapy in HCC.