The invention discloses a locking device and an anti-counterfeiting packaging box. The locking device comprises a lock tongue and a lock catch. The lock tongue comprises a base plate, and protrusions are arranged on the surface of the base plate. A first sawtooth part is arranged on the surfaces of the protrusions. The lock catch comprises a base. The surface of the base extends to form an inserting groove parallel to the base. A second sawtooth part corresponding to the first sawtooth part is arranged on the inner wall of the top of the inserting groove. After the base plate is inserted into the inserting groove, the first sawtooth part and the second sawtooth part can be engaged with each other. The anti-counterfeiting packaging box comprises a box body, an anti-counterfeiting layer, a box opening block and the locking device. The base is inlaid into the box opening block and the inserting groove is exposed out of the surface of the box opening block. The box body comprises a box main body and a box cover. The lock tongue is inlaid into the edge of the box cover. The box opening block is in easy-to-dismount connection with the box wall of the box main body. After the box cover and the box main body are covered, the first sawtooth part and the second sawtooth part are engaged with each other. When the box cover needs to be opened, the box main body or the box cover has to be destroyed, and therefore the phenomenon that the box main body and the box cover are reassembled after the box cover is opened can be prevented.