The invention discloses a combined expansion rod, which comprises a round rod body. An expansion sleeve with a conical front end is sleeved on the rod body. The key point of the technical scheme of the invention is that: the front end of the rod body is provided with a detachable and replaceable expansion head component; the expansion head component comprises an expansion head; and a detachable connection structure is arranged between the expansion head and the expansion sleeve. The invention aims to overcome the defects in the prior art and provide the combined expansion rod in which an expansion head ring and the expansion sleeve are replaced by detaching the expansion head component.