Terahertz biomedical sensor is a hot spot in the current research. Its implementation method is mainly based on the use of metamaterials or two-dimensional materials to construct electromagnetic subwavelength structures. When terahertz waves interact with the structures, they cause phenomena similar to surface plasmon resonance and generate local electromagnetic field enhancement effects. The enhanced electric field improves the interaction between light and biological samples, resulting in a change in spectral response, enabling highly sensitive detection and analysis of biomolecules. Based on the research status in recent years, this paper expounds the types of biosensors and their applications in biomedicine and other fields, and discusses the future challenges and development prospects. It hopes to provide some valuable suggestions.