Exosomes are membranous vesicles secreted by most eukaryotic cells， which are approximately 30-150 nm in diameter and contain RNA， proteins and lipids closely related to their function and origin， playing an important role in cell-to-cell communication. It can promote tumor progression by promoting the proliferation and migration of tumor cells， improving the tumor microenvironment and inhibiting the immune response. In addition， exosomes are expressed at high levels in certain tumors and can be used as predictors of cancer for early diagnosis. It can also be used as a carrier to carry targeted drugs to the local tumor to exert an inhibitory effect.