The present disclosure provides a positioning device for a printing
machine, belonging to the technical field of printing machines, comprising: a shell, a conveying belt is rotatably arranged in the shell through a driving mechanism, and the outer wall of the conveying belt is in contact with the inner wall of the shell, a plurality of adsorption holes are evenly arranged on the conveying belt, and a gas pump is arranged in the conveying belt. When the improved positioning device for the printing
machine is used, the printing material is moved to the required position through the conveying belt, and an adsorption force is generated between the conveying belt and the printing material through the gas pump, so that the position deviation of the printing material caused by external
airflow is avoided, the printing effect of the printing
machine is affected, a directional
airflow is formed on the top side of the printing material, the cleaning of the attached objects on the printing material is completed before printing, and the printed patterns on the printing material are dried after printing, so that the printing effect of the printing machine is good.