Abstract: As one of the important effector molecules of RNA interference, small interference RNA(siRNA) has great potential to treat a variety of diseases. At present, three siRNA drugs have been approved by the Food and Drug Administration, and dozens of siRNA drugs are in clinical trials. Non-viral vectors such as lipid nanoparticle, N-acetylgalactosamine(GalNAc)-siRNA conjugate, polymer and biomimetic vector provide good solutions to the problems of easy degradation and clearance of siRNA in vivo, immunogenicity and weak permeability of cell membrane. With the deepened study of disease gene spectrum and non-viral vector, more and more siRNA drugs have entered preclinical studies and clinical trials. This paper systematically reviews and analyzes the development process of siRNA drugs, biological barriers in the process of in vivo application and the structure and function of delivery carriers, in order to provide reference for the future development of siRNA drugs.