Automatic tube expander

The invention provides an automatic tube expander comprising a rack and a controller. A tube expanding station is arranged on the rack, and a plurality of supporting units which are distributed from left to right and used for supporting paper tubes are arranged in the tube expanding station. A feeding groove is fixed to the rack on the left side of the tube expanding station, and a discharging groove is fixed to the rack on the right side of the tube expanding station. Sliding plates are connected to the positions, below the feeding groove and the tube expanding station, of the rack in a sliding mode, a jacking mechanism is installed on each sliding plate, and a first driving mechanism used for simultaneously driving the two sliding plates to slide is installed on the rack. A moving platform is installed on the rack located on the rear side of the tube expanding station in a front-back sliding mode, a second driving mechanism used for driving the moving platform to move front and backis installed on the rack,