The invention discloses a single-cylinder bidirectional screen printing machine. The single-cylinder bidirectional screen printing machine comprises a machine frame, a traveling rail device, positioning devices and an adhesive tape machine; the adhesive tape machine is installed on the machine frame; the traveling rail device is fixed to one side of the machine frame, and the positioning device isslidably connected with the traveling rail device; the traveling rail device is provided with a traveling mechanism; a connection arm is arranged on the traveling mechanism; a work arm arranged in the vertical direction is installed at the end of the connection arm, the upper portion of the work arm is provided with an air cylinder installation groove, and the lower portion of the work arm is provided with a work rod installation groove; the middle of the work rod is arranged in the work rod installation groove, and the work rod and the work rod installation groove are rotationally connected;one end of a push-pull air cylinder is rotationally connected with the air cylinder installation groove, and the other end of the push-pull air cylinder is rotationally connected with one end of thework rod; and the bottoms of the two ends of the work rod are each provided with a scraper blade installation groove, and scraper blades are installed on the two scraper blade installation grooves. The single-cylinder bidirectional screen printing machine has the advantages of being simple in structure and high in working efficiency, and the problem that in the prior art, a printed pattern of a screen printing machine is prone to deviating can be effectively solved.