Barrel box bubble pressing method, barrel box bubble pressing mechanism and barrel box opening face paper inward folding method

The invention discloses a barrel box bubble pressing method, a barrel box bubble pressing mechanism and a barrel box opening face paper inward folding method. The barrel box bubble pressing method comprises the following steps that a barrel box is installed on an inner mold in a sleeving mode, wherein the side walls of the barrel box comprise the two opposite first side walls and the two opposite second side walls; the inner mold and the barrel box are moved to a bubble pressing station, the two first side walls and/or the two second side walls of the barrel box are extruded to be tightly attached to the inner mold, and bubble pressing is conducted; and the inner mold and the barrel box continue to be moved to a discharging station, and the inner mold and the barrel box are separated. A barrel box bubble pressing technology is changed, in a barrel box bubble pressing process, by rotating the inner mold, conversion among stations is achieved by rotating the inner mold, meanwhile, in the bubble pressing process