Common kinds of chemotherapy may cause harm to normal cells and tissues. Localised chemotherapy, unlike systemic chemotherapy, can lessen side effects by providing a consistent supply of chemotherapeutic chemicals directly to the tumour location. This emphasises the importance of controlled-release biodegradable hydrogels as chemotherapeutic drug delivery systems. This study looks at employing hydrogels as drug delivery methods for HCC, including thermosensitive, pH-sensitive, photosensitive, dual-sensitive, and glutathione-responsive hydrogels. Hydrogel-based drug delivery systems outperform traditional systemic chemotherapy in cancer treatment. Cancer immunotherapy has emerged as the new paradigm for cancer treatment. The development and discovery of new therapeutic molecules has increased the use of immunotherapy in clinical studies. This article discusses the current state of functional hydrogels for effective cancer immunotherapy. First, we will discuss the fundamental principles of cancer immunotherapy and the benefits of employing hydrogels to implement these mechanisms. Finally, we briefly explore the existing issues and potential applications of hydrogels for effective cancer immunotherapy. Keywords: Cancer, Hydrogel-based controlled drug delivery system, postoperative radiotherapy, chemotherapy, Immunotherapy.