Automatic filling device

The utility model relates to the technical field of liquid filling, in particular to an automatic filling device which comprises a supporting frame, a liquid injection box and a filling head, the liquid injection box is fixedly connected to the middle of the upper end of the supporting frame, a sliding filling pipe is connected to the lower end of the inner side of the liquid injection box in a sealed mode, and the filling head is connected to the lower end of the sliding filling pipe in a sealed mode. The outer side of the upper end of the supporting frame is rotationally connected with a rotating annular plate, and the inner side of the rotating annular plate is slidably connected with a sliding rod. And meanwhile, the sliding filling pipe moves upwards under the jacking pressure of the filling bottle, so that the liquid can be injected into the filling bottle through the sliding filling pipe, the supporting frame and the filling bottle can be downwards separated from the filling head under the action of a