The present subject matter discloses a plastic storage box with an integrated hinge structure. The plastic storage box comprises a cover board being pivotably connected to a rear board. The cover board is divided into an upper turning portion and a lower turning portion by an embedded groove hinge. When the cover board is coupled to the rear board, the upper turning portion of the cover board is pivotable in relation to the rear board. The embedded groove hinge eliminates the need for a traditional hinge. The remaining boards of the storage box can be detachably connected to their respective adjacent boards. Furthermore, the package volume of the boards for the storage box is compact, the packaging is convenient, and the boards are securely stored during transportation.