The invention discloses an efficient and energy-saving paper bag production device. The efficient and energy-saving paper bag production device comprises a feeding device, a folding device, a cut-off device and an edge sealing device, all of which are sequentially arranged on an assembly line. The paper bag production device further comprises a paper bag size adjusting device. The paper bag size adjusting device comprises a first rack, a second rack, a first adjusting plate, a second adjusting plate, a first guide rod, a second guide rod, a lead screw, a first chain, a first chain wheel, a second chain wheel and a motor. The first adjusting plate and the second adjusting plate are oppositely arranged in a spaced manner, the two ends of the first adjusting plate are arranged on a first guide rod in a sleeving manner, and the two ends of the second adjusting plate are arranged on a second guide rod in a sleeving manner. The lead screw is provided with a positive thread part and a negative thread part which are arranged at the two ends respectively. A first thread part is arranged in the middle of the first adjusting plate, a second thread part is arranged in the middle of the second adjusting plate, the first thread part is in threaded fit with the positive thread part, and the second thread part is in threaded fit with the negative thread part. By means of the efficient and energy-saving paper bag production device, the width of a paper bag can be adjusted very conveniently, production can be achieved without shutdown, and the effects of being high in efficiency and saving energy are achieved.