A reusable packaging box comprising: a bottom unit that has a receiving space in which a product is received; a lower body and an upper body that are provided to each have a box shape with open top and bottom to be coupled to a top of the bottom unit, comprise left and right plates (121, 131) and comprise front and back plates (127, 137) hinge-coupled by a plurality of second and third connection units (133b, 137a) to the left and right plates (121, 131) such that the front and back plates (127, 137) are rotatable in the left and right directions, wherein said plurality of second connection units protrude from the sides of the left and right plates to be connected to the front and back plates, and said plurality of third connection units protrude from the front and back plates to form a plurality of grooves into which the plurality of second connection units are inserted, wherein the upper body and the lower body are storable after being folded in order to reuse the reusable packaging box; and a lid that has a receiving space in which the product is received and is coupled to the top of the upper body, wherein each of the bottom unit, the upper body and the lower body, and the lid is formed of a material that absorbs an impact and thus performs both a function of absorbing an impact and a function of packaging an outside of the product, characterized in that said left and right plates (121, 131) each comprises two side plates (123, 133) coupled to a plurality of hinge members, each hinge member having a double hinge structure such that the two side plates are rotatable in left and right directions, wherein the left and right plates (121, 131) comprise a plurality of coupling grooves into which the plurality of hinge members are inserted and coupled, the plurality of coupling grooves are formed by a plurality of first connection units that protrude from adjacent sides of the sides plates (123, 133) of the left and right plates. a bottom unit that has a receiving space in which a product is received; a lower body and an upper body that are provided to each have a box shape with open top and bottom to be coupled to a top of the bottom unit, comprise left and right plates (121, 131) and comprise front and back plates (127, 137) hinge-coupled by a plurality of second and third connection units (133b, 137a) to the left and right plates (121, 131) such that the front and back plates (127, 137) are rotatable in the left and right directions, wherein said plurality of second connection units protrude from the sides of the left and right plates to be connected to the front and back plates, and said plurality of third connection units protrude from the front and back plates to form a plurality of grooves into which the plurality of second connection units are inserted, wherein the upper body and the lower body are storable after being folded in order to reuse the reusable packaging box; and a lid that has a receiving space in which the product is received and is coupled to the top of the upper body, wherein each of the bottom unit, the upper body and the lower body, and the lid is formed of a material that absorbs an impact and thus performs both a function of absorbing an impact and a function of packaging an outside of the product, characterized in that said left and right plates (121, 131) each comprises two side plates (123, 133) coupled to a plurality of hinge members, each hinge member having a double hinge structure such that the two side plates are rotatable in left and right directions, wherein the left and right plates (121, 131) comprise a plurality of coupling grooves into which the plurality of hinge members are inserted and coupled, the plurality of coupling grooves are formed by a plurality of first connection units that protrude from adjacent sides of the sides plates (123, 133) of the left and right plates.