A printing head cleaning device for an inkjet printer, comprising: a waste ink tray; a wiping blade installed in the waste ink tray and configured to clean a printing head of the inkjet printer; a rotation means installed in the waste ink tray and configured to rotate the wiping blade such that the wiping blade is stood up or lain down; and a cleaning means installed in the waste ink tray and configured to clean the wiping blade by contacting the wiping blade when the wiping blade is rotated, wherein the rotation means comprises a support member configured to support the wiping blade, a rotating shaft rotatably provided on both side walls of the waste ink tray and coupled to both ends of the support member, and a driving means configured to rotate the rotating shaft to a predetermined angle, wherein a cover plate for covering the waste ink tray is installed in the waste ink tray, and a wiping blade protrusion opening is provided in the cover plate in such a way as to penetrate the cover plate, and the wiping blade protrusion opening is provided to enable an upper end of the wiping blade to protrude above the cover plate, characterized in that a cover member is installed in the support member such that the cover member is rotated together with the support member and the wiping blade, when the wiping blade is rotated to be lain down, the cover member is rotated upwards and covers the wiping blade protrusion opening, and when the wiping blade is rotated to be stood up, the cover member is rotated downwards so as not to cover the wiping blade protrusion opening, wherein a discharge hole for discharging ink and foreign materials flowing down along the wiping blade is provided in the cover member in such a way as to penetrate the cover member. a waste ink tray; a wiping blade installed in the waste ink tray and configured to clean a printing head of the inkjet printer; a rotation means installed in the waste ink tray and configured to rotate the wiping blade such that the wiping blade is stood up or lain down; and a cleaning means installed in the waste ink tray and configured to clean the wiping blade by contacting the wiping blade when the wiping blade is rotated, wherein the rotation means comprises a support member configured to support the wiping blade, a rotating shaft rotatably provided on both side walls of the waste ink tray and coupled to both ends of the support member, and a driving means configured to rotate the rotating shaft to a predetermined angle, wherein a cover plate for covering the waste ink tray is installed in the waste ink tray, and a wiping blade protrusion opening is provided in the cover plate in such a way as to penetrate the cover plate, and the wiping blade protrusion opening is provided to enable an upper end of the wiping blade to protrude above the cover plate, characterized in that a cover member is installed in the support member such that the cover member is rotated together with the support member and the wiping blade, when the wiping blade is rotated to be lain down, the cover member is rotated upwards and covers the wiping blade protrusion opening, and when the wiping blade is rotated to be stood up, the cover member is rotated downwards so as not to cover the wiping blade protrusion opening, wherein a discharge hole for discharging ink and foreign materials flowing down along the wiping blade is provided in the cover member in such a way as to penetrate the cover member.