The invention relates to a wrinkle removing device before plastic film printing. The defects that in the prior art, a printing device cannot ensure flatness of a printing film in the printing process, and the quality of product printing is poor are overcome. According to the wrinkle removing device before plastic film printing, a heating guide roller is rotatably connected to a rack, a draught fan is arranged on the rack, and supplies air to an air storage chamber, air in the air storage chamber blows to the plastic film on the heating guide roller through air guide pipes and air outlet holes in the air guide pipes, the heating guide roller plays a flattening role in the plastic film, the heating guide roller heats the plastic film, flattening of the plastic film is facilitated, the plastic film is rapidly cooled by the air blown out of the air outlet holes after being flattened, and finally the plastic film enters a printing system. According to the device, the flatness of the plastic film is greatly improved, in the subsequent printing process, the product printing quality is greatly improved, the product scrapping is reduced, and the product printing cost is reduced.