Abstract: The present invention discloses a nucleic acids extraction system and method based on a 3D-printed microdevice, and belongs to the technical field of nucleic acids extraction. The nucleic acids extraction system is a monomer 3D-printed microdevice or a 3D-printed microdevice prepared by 3D printing technologies, the monomer 3D-printed microdevice comprises a nucleic acids binding region and a handle region, and the 3D-printed microdevice is composed of more than two monomer 3D-printed microdevices through a joining region; and the nucleic acids binding region is made of photosensitive resin or thermoplastic. An extraction method for the nucleic acids extraction system based on a 3D-printed microdevice is used to bind, clean and elute nucleic acids by moving the monomer 3D-printed microdevice or the 3D-printed microdevice among a solution containing target nucleic acids, a washing buffer and an elution buffer.