The invention relates to a novel protection covering box of a printer. The box comprises a box body, wherein the inner cavity of the box body is larger that the size of the printer slightly. Guide rails are symmetrically arranged at the front and back of the top surface of the box body; and a support plate is installed between the two opposite guide rails in a sliding mode. Hanging holes are respectively formed in the left side surface and the right side surface of the box body; hooks are movably installed in the hanging holes; and object placing boxes are hung at the hooks. The front side panel of the box body and the box body are connected in an openable and closable mode. An operation opening, a paper placing opening, and a paper taking opening are formed in the front side panel; and an operation opening shielding plate, a paper placing opening shielding plate, and a paper taking opening shielding plate are respectively hinged to the operation opening, the paper placing opening, and the paper taking opening. A base plate of the box body can slide forward and backward relative to the box body; rollers are symmetrically installed at the two ends of the base plate; chutes are formed in the two sides of the box body symmetrically; and the rollers are installed in the chutes in a rolling mode. According to the invention, dustproof protection of a printer can be realized; the space can be utilized reasonably and recycling of the space is realized; and the object placing function is added, so that the practicability of the covering box is high.