The invention discloses a filling bottle air leakage detection device, which is used to detect the airtightness of the filling bottle having an opening. The filling bottle air leakage detection device comprises a rack body, in which are disposed a first piston rod and a second piston rod. A spring is disposed between the first piston rod and the second piston rod, and a pressure sensor is disposed on the spring. One end of the first piston rod extended out of the rack body is connected with a driving mechanism, and the first piston rod is used to drive the second piston rod to carry out a uniform motion along the axial direction of the second piston rod. One end of the second piston rod extended out of the rack is clamped in the filling bottle through the opening, and is connected with the opening of the filling bottle in a dynamically-sealed way. The pressure sensor is connected with a display terminal by a data processing module. The air leakage of the filling bottle is detected accurately, and the filling bottle air leakage detection device is suitable for assembly line production.