The present invention provides a method of using a two-stage nucleic acid reaction and detection tube. First, a reaction and detection tube is provided. Then a reaction is performed by using a liquid in the storing space of the second tube, following by putting the dipstick into the dipstick fixing space of the connector. The first tube, the second tube and the connector is assembled together, wherein the dipstick is placed both in the dipstick fixing space of the connector and the detection space of the first tube. The reaction and detection tube is rotated from bottom to top, thus making the liquid in the storing space of the second tube flow into the liquid collection space through the diversion unit and then contact the dipstick in the dipstick fixing space. A detection result is then observed from the dipstick.