A nucleic acid integrated detection method and detection reagent tube are provided, separating a lysis solution, a cleaning solution and a reaction solution in a detection reagent tube by providing a plurality of separation plugs in an over-under arrangement and disposing a hydrophobic layer in liquid or solid phase on each separation plug; adding a sample into the lysis solution; extracting nucleic acid in the sample using magnetic nanobeads; and then driving the magnetic nanobeads carrying the nucleic acid to sequentially pass through each hydrophobic layer along a magnetic bead channel and into the cleaning solution and the reaction solution to realize a cleaning and amplification for the nucleic acid, and finally, detecting the nucleic acid of the sample by an external device using an optical detection method, thus realizing a plurality of steps of nucleic acid extraction, cleaning and amplification reactions in the same detection reagent tube.