Ashkin et al. proved that laser radiation pressure can be used to manipulate bacteria and viruses in bioscience, and officially named “optical tweezers”. Nowadays, the technology of optical tweezers has become one of the most powerful tools in the field of biology, but with the reduction of the scale of capturing objects, due to the existence of Brownian motion and laser diffraction limit, traditional optical tweezers are difficult to achieve stable capture. The emergence of nano-optical tweezers brings the possibility of capturing and manipulating nano-scale objects. Nano-optical tweezers have great application value and development potential in biomedical, quantum science, material science and other fields. In biomedical research, it can capture and manipulate tiny particles such as biological cells, DNA molecules, bacteria and viruses. In the research of quantum science, optical tweezers array, as a platform of quantum system, affects the subfields of quantum optics, quantum networks, cold quantum computing and atomic computing. In the research of material science, the emergence of nano-optical tweezers makes it possible to analyze individual nanoparticles by fluorescence spectrum, Raman spectrum and absorption spectrum. This paper introduces the basic principle of nano-optical tweezers, summarizes four kinds of nano-optical tweezers: fiber optical tweezers, waveguide optical tweezers, photonic crystal optical tweezers and plasmon optical tweezers, and introduces their main applications in manipulating nanoparticles and biomolecules.