To provide a method for smashing the ink of a printer capable of smashing the ink on an ink roller without consuming a waste printing sheet.

The method for smashing the ink of the printer comprises: an ink transfer step of transferring the ink on the ink roller by rotating a form roller and a plate cylinder in the state in which the form roller is brought into contact with a printing plate mounted on the outer periphery of the cylinder after the supply of the ink to the ink roller is stopped; an ink transfer step of transferring the ink on the printing plate to a blanket by rotating the cylinder and the blanket cylinder in the state in which the printing plate mounted on the outer periphery of the cylinder is brought into contact with the blanket mounted on the outer periphery of the cylinder, a plate delivery step of delivering the printing plate in which the ink is transferred from the ink roller; and a blanket cleaning step of cleaning the blanket.