The invention discloses a nucleic-acid extraction, amplification and detection integrated device and a manufacturing method and a detection method thereof. The nucleic-acid extraction, amplification and detection integrated device comprises a light-cured-resin upper cover printed by the 3D printing technology and a base; the upper cover comprises a sample feeding hole, a control button, a U-shaped clamping fixing hole and a test paper result observation window; an integrated module on the base comprises a paper-base nucleic acid extraction module, an isothermal amplification module and a side-flow test paper detection module; the paper-base nucleic acid extraction module comprises a liquid storage tank, a pyrolysis channel, a washing channel, nucleic acid adsorption paper and a water absorption pad; the isothermal amplification module comprises a heating slice, a U-shaped clamp, a button battery and a PMMA plastic plate; a test-paper detection module comprises a test paper strip and a chromatographic solution storage tank. Finally, the upper cover is pressed on the base, and device assembling is completed. According to the paper-base nucleic acid extraction, amplification and detection integrated device, external device and professional technical persons are not required, and the paper-base nucleic acid extraction, amplification and detection integrated device has the advantages of being low in cost, easy to operate, rapid, easy to carry and the like, and is suitable for the field of molecular diagnosis, and particularly is suitable for resource-lack remote areas.