The fully automatic square bottom paper bag machine is used to produce environmentally friendly paper bags, food paper bags, shopping paper bags, and various types of hand-held paper bags made from paper as raw materials. The machine completes the bag making process of raw color paper or printed roll paper in one go, from top gluing, folding into a tube, cutting the paper tube, bottom indentation, bottom gluing, bag bottom forming, and bag discharge with automatic functions. This machine adopts an original Japanese imported electronic control system, controlled by servo motors to produce paper bag lengths and finished product feeding. It has high accuracy, strong stability, easy maintenance, and efficient production. It is an ideal equipment for major printing factories and manufacturers of hand-held paper bags.