Bone fusion nail

The utility model belongs to the technical field of medical instruments, and discloses a bone fusion nail. The bone fusion nail is used for connecting at least two to-be-fractured structures, the bone fusion nail comprises a first connecting piece and a second connecting piece, the first connecting piece has a contraction state and an expansion state, the first connecting piece can be implanted into the to-be-fractured structures in the contraction state, and the second connecting piece can be implanted into the to-be-fractured structures in the expansion state. In the expansion state, the first connecting piece can fix the position of the bone fusion nail and the position of a to-be-set structure; the first connecting piece is connected with the second connecting piece, an external thread is arranged on the second connecting piece, a first open groove is formed in the external thread, and the first open groove spirally extends in the axis direction of the second connecting piece. Through the arrangement of t