The invention discloses a simple packing box, and relates to the technical field of packing goods. The packing box comprises a bottom box; the bottom box is opened at the upper end, and consists of multiple side plates and a baseplate; a connecting belt consists of a first connecting belt and a second connecting belt; a crease is arranged in the connecting place between the first connecting belt and the second connecting belt; the shape and the size of the first connecting belt are adapted to the shape and the size of any one side plate, so that the first connecting belt is bonded with the side plate; the shape and the size of the second connecting belt are adapted to the shape and the size of the opening at the upper end of the bottom box; after folding along the crease, the second connecting belt can cover the opening of the bottom box; and a cover plate is bonded with the second connecting belt, and is connected to the bottom box in an overturning manner. The packing box assembled by three plates is adopted to replace a single-piece packing box structure, so that the problems of complicated process, high production cost and shortage of excellent showing effect in traditional split packing box and leather shell box are solved.