The invention discloses an automatic uncapping device for bottled water and a water drinking device. The automatic uncapping device for bottled water comprises a shell, a bottle cap perforating mechanism and a bottle body fixing mechanism, wherein the bottle cap perforating mechanism and the bottle body fixing mechanism are arranged in the shell, the bottle cap perforating mechanism comprises a motor, a cam, a positioning piece, perforated pipes and a limiting sensor, and the cam is fixedly connected with a rotating shaft of the motor; the positioning piece is connected to the position, close to the edge, of the cam, and the perforated pipes are arranged on the positioning piece and connected with a water discharging pipe; the bottle body fixing mechanism comprises a top plate arranged at the top of the shell, a first hole used for fixing bottled water is formed in the top plate, the bottled water is inversely arranged in the first hole, and a bottle cap of the bottled water is located over the perforated pipes; and the water drinking device comprises a bottled water uncapping device and a heating device, and the cam drives the perforated pipes on the positioning piece to upwards break the bottle cap. According to the automatic uncapping device for the bottled water and the water drinking device, automatic uncapping of the bottled water can be achieved, man-made pollution is avoided, the structure is simple, and use is convenient.