The invention provides a Luban lock. The Luban lock is formed by five building blocks A, B, C, D and E, the sizes and the shapes of two building blocks B and E are consistent, the building block A isprovided with a first square groove and a second square groove, the second square groove is vertically arranged at the middle part of an opposite surface of the first square groove, the middle part ofthe first square groove communicates with one end of the second square groove, the building block B is provided with a first groove and a second groove, the second groove is vertically arranged on anopposite surface of the first groove, one side of the second groove communicates with one end of the first groove, the building block C is provided with a first through groove and a second through groove, the second through groove is vertically arranged on an adjacent surface of the first through groove, one side of the second through groove communicates with one end of the first through groove,the building block D is provided with a first long groove and a second long groove, the second long groove and the first long groove are arranged on the same side surface, the second long groove communicates with one portion of the first long groove, and the five building blocks A, B, C, D and E are connected in sequence to form an interlocking structure.