A detection apparatus of long stroke leading screw installation precision and an application method thereof relate to the detection apparatus of a driving leading screw of a numerical control turret punch and a numerical control laser cutting machine workbench and the application method thereof. The detection apparatus of the long stroke leading screw installation precision and the application method thereof are provided. By using the apparatus and the method of the invention, under the condition of conforming to a natural law, detection data can be accurately obtained and the product installation precision can be increased. The leading screw is flexibly connected on a rack. A pair of Y direction guide rails which is parallel to the leading screw is arranged on the rack. A leading screw nut is connected on the leading screw. The detection apparatus comprises a portal frame, an X axis guide rail, an X axis slide block, a table 1 and a table 2. The application method of the invention comprises the following steps: 1) Installing the detection apparatus on the pair of the Y direction guide rails; 2) Moving the leading screw nut to a middle position of the leading screw; 3) Overcoming deflection; 4) Detecting one end; 5) Detecting the other end; 6) Finishing.