Color press for plastic bags

The utility model belongs to the field of color printing machines, particularly relates to a color printing machine for a plastic bag, and aims to solve the problems that a plastic bag stretching and flattening mechanism is lacked, the plastic bag is easy to wrinkle when being used, and a color printing pattern is misplaced, the following scheme is provided: the color printing machine comprises a shell, a conveying mechanism is arranged in the shell, and the conveying mechanism is arranged in the shell; a control box is fixedly installed at the top of the shell, a hydraulic cylinder is fixedly installed at the top of the control box, an output shaft of the hydraulic cylinder extends into the control box and is fixedly provided with a U-shaped frame, a color printing mechanism is installed on the U-shaped frame, a frame plate is fixedly installed at the bottom end of the U-shaped frame, and two triangular bases are installed on the inner wall of the front side and the inner wall of the rear side of the control