The bottom machine is an unsealed paper tube (either manually placed in the bottom cardboard or not in the cardboard). After automatic conveying, automatic glue spraying, automatic paste bottom, automatic compaction and other processes, the output is a back cover paper bag. The machine is operated by touch screen and equipped with four spray guns. The user can adjust the thickness of the glue and the position of the glue according to the bag making requirements. The mechanism bag is evenly sprayed, the bag making precision is high, and the speed is fast, and the tote bag of various specifications can be produced.