Printing machine for printing plastic packaging bags

The invention belongs to the technical field of printing machines, and discloses a printing machine for printing plastic packaging bags. The printing machine comprises a machine body, a base is fixedly connected to the bottom of the machine body in the horizontal direction, supporting legs are fixedly connected to one side of the bottom of the base, and a top plate is fixedly connected to the top of the machine body in the horizontal direction; and an observing window is mounted at one side of the outer portion of the machine body, and a controller is mounted at the lower portion, close to the observing window, of the outside of the machine body. The printing machine is provided with a movable plate device, a movable plate can horizontally move above the interior of the machine body in the horizontal direction along a threaded rod along with a sliding base under the condition that the threaded rod rotates, therefore, a printing roller below the movable plate can be driven to conduct large-range complete print