Box sealing device of automatic boxing machine

A box sealing device of an automatic boxing machine comprises a mounting plate, a guiding and conveying component, a box conveying component and a box sealing component, the box sealing component comprises a left folding mechanism and a right folding mechanism which are identical in structure and symmetrically arranged, and the guiding and conveying component is arranged between the left folding mechanism and the right folding mechanism; the left folding mechanism and the right folding mechanism each comprise a first air cylinder, a second air cylinder and a third air cylinder, and the third air cylinders drive box folding pieces fixed to rocker arms to swing around the centers of rocker arm shafts so as to complete folding and closing of the side covers of the packaging boxes. The second cylinder drives the rocker arm to drive the paper folding sheet to swing around the center of the rocker arm shaft so as to limit the folding center around the edge of the side plate when the insertion tongue is folded; the