Abstract: Exosomes are extracellular vesicles composed of lipid bilayer membrane structures, which belong to a subgroup of extracellular vesicles.Exosomes are secreted extracellularly by multi-step endocytosis of normal cells and cancer cells.Exosomes carry a variety of functional molecules such as proteins, lipids, nucleic acids (DNA and RNA), metabolites, etc., and facilitate intercellular communication.Exosomes of tumor cell, stromal cell, and immune cell origin play an important role in tumor formation, metastasis of primary foci and immune escape.Exosome has been used as biomarkers for the early-stage detection of cancer and therapeutic monitoring because exosomes carry contents derived from source cells, and some molecules are significantly different in cancer cell-derived and normal cell-derived exosomes and can be used as biomarkers for early cancer diagnosis as well as for therapeutic monitoring.Biosensorbased cancer-associated exosome detection has been widely studied in recent years.The biosensors used for exosome detection include two major categories: (1) Biosensors based on electrical signals; (2) Biosensors based on optical signals.In this paper, the progress of traditional exosome detection techniques and their shortcomings in disease diagnosis were analyzed and different types of biosensors in detecting protein and nucleic acid in cancer-associated exosomes were summarized.Meanwhile, the challenge faced by biosensor-based exosome detection was discussed, and the prospect of the development of biosensor-based exosome detection in the future was forecasted.