When cleaning the flexo printing machine, the type of cleaning fluid to be selected must consider two aspects: one is that it should match the type of ink used; the other is that it cannot cause swelling or corrosion to the printing plate. Before printing, the printing plate should be cleaned with cleaning solution to ensure that the surface of the printing plate is clean and free of dirt. After shutdown, the printing plate should be cleaned immediately to prevent the printed ink from drying and solidifying on the surface of the printing plate.