The invention discloses a packing box which comprises a box body, connecting clamping plates and an external packing strip, wherein the box body is formed by an upper box cover, a lower box cover and a box main body, the connecting clamping plates are connected with the box body, and the external packing strip is used for conducting combined package. The packing box is a combined type packing box which is formed by a flat plate in a folding and inserted combination mode after the flat plate is pressed and cut through a cutting die. The packing box can be transported to a use place in a mode of the flat plate. In the process of the assembly of the packing box, any adhesives are not needed, and the packing box after being assembled can be arrayed and changed in a various-state mode. After the lower box cover and a clamping design at the bottom of the box main body are tightly combined, the lower box cover and the box main body are not easy to separate, and a fastening function of reinforcing the small packing box is played. Due to the fact that the connecting clamping plates are inserted and connected with the upper box cover and the lower box cover of the small packing box, connected combination package is formed, and the combination is various, free and convenient. The external packing strip not only has the decorative and beautiful functions, but also can fasten the whole package. The packing box is enabled to be combined into a complete packing article. Due to the fact that structural dislocation is considered when the packing box is designed, any adhesives are also not needed when the external packing strip is used, and simple packing and use of the packing box can be conducted.