Due to the excellent performance of two-dimensional materials compared with conventional materials in many aspects, researchers have paid extensive attention to two-dimensional materials. At present, two-dimensional materials have become a research hotspot in various fields, and are widely used in biomedicine, electronics, optoelectronics and catalysis. This paper mainly summarizes and discusses the application of two-dimensional materials in optical sensing in the biomedical field. This paper mainly discusses the generation and development of two-dimensional materials, the advantages and disadvantages of two-dimensional materials and the types, principles and manufacturing methods of optical biosensors based on two-dimensional materials, as well as some achievements of these sensors in single-cell, RNA, protein molecule highly sensitive detection technology, and combines these results to briefly analyze some advantages of experimental schemes using two-dimensional materials compared with traditional methods. Finally, the development status of two-dimensional materials is briefly summarized, and their future development is prospected.