The invention discloses a thread-type eccentric crescent moon combination bolt and a mounting method of the thread-type eccentric crescent moon combination bolt. The thread-type eccentric crescent moon combination bolt comprises a bolt composed of a bolt head and a screw which are connected. The thread-type eccentric crescent moon combination bolt is characterized by further comprising an inner-crescent-type eccentric crescent moon piece. The inner-crescent-type eccentric crescent moon piece comprises a rod piece and an eccentric threaded through hole, wherein the eccentric threaded through hole is formed on the rod piece and penetrates from the head portion of the rod piece to the end portion of the rod piece. The rod piece with the eccentric threaded through hole is screwed on the screw through the eccentric threaded through hole in a threaded connection mode. Therefore, when the thread-type eccentric crescent moon combination bolt is mounted, the eccentric threaded through hole of the inner-crescent-type eccentric crescent moon piece is screwed on the screw of the bolt and is screwed inside a hole to form an assembly of the bolt head inside the hole, can not be drawn out and is firm, then decorative panels are mounted on a building main body through a hook piece, a hanging seat and adjustment of front and rear bolts.