Closed nucleic acid extraction kit

The utility model provides a closed nucleic acid extraction kit. The closed nucleic acid extraction kit comprises a base; a kit body; the kit body is provided with a plurality of accommodating cavities, a plurality of first runners and a plurality of second runners; a closed structure is arranged at the outlet of the first runner; the top and the bottom of the accommodating cavity are respectively communicated with a first flow channel and a second flow channel; the accommodating cavity is used for accommodating a reagent or a sample; the sliding part is connected to the kit body in a sliding manner; the sliding piece is provided with a cavity and a concave cavity; one end of the cavity is connected with an injector, and the other end is communicated with one side of the cavity; a first through hole is formed in the bottom wall of the cavity; and the reaction tube is connected to the kit body and is respectively communicated with a first flow channel and a second flow channel. The whole structure is small and