The invention discloses a multi-caliber three-dimensional molding extrusion head used for additive manufacturing. The multi-caliber three-dimensional molding extrusion head comprises a spraying head which is fixedly arranged, the spraying head comprises a material guide pipe used for conveying consumable items and arranged in a manner of being coaxial with the spraying head, the material guide pipe and a material storing pipe are in sleeve connection in a sliding manner, and the material guide pipe can move along the self axis; the spraying head further comprises an extrusion opening outer wall and a flow control body, and the flow control body and the inner wall of the extrusion opening outer wall can be switched between the matched state and the separating state along with changes of theextrusion quantity; a feeding port of the spraying head is further provided with a threaded connecting piece used for fixing the spraying head, the lower end of the threaded connecting piece is connected with the extrusion opening outer wall of the spraying head, and an avoiding cavity is formed between the threaded connecting piece and the extrusion opening outer wall; and a spring enabling theflow control body to be far away from the threaded connecting piece is arranged between the flow control body and the threaded connecting piece.