The utility model relates to the field of tools and provides a dowel assembling and disassembling tool which comprises a tool frame, a hollow bolt, a supporting pillar, a guide shaft and a thrust shaft. The tool frame is of a U shape, one end of the U shape is provided with a threaded hole, and the other end of the U shape is provided with a through hole. A round hole is formed in the axis of a screw rod of the hollow bolt. The size of the round hole is larger than the outer diameter of a dowel needing to be assembled or disassembled. The screw rod of the hollow bolt is provided with threads matched with the threaded hole of the tool frame. The supporting pillar is of a bolt shape. The size of a screw rod of the supporting pillar is matched with the size of the round hole of the hollow bolt. A round concave hole is formed in the head of the screw rod of the supporting pillar. The guide shaft is of a bolt shape. The size of a screw rod of the guide shaft is matched with the dowel needing to be assembled or disassembled. The head of the screw rod of the guide shaft is matched with the size of the through hole of the tool frame. The thrust shaft is of a bolt shape. The size of a screw rod of the thrust shaft is matched with the dowel hole needing to be assembled or disassembled, and the outer diameter of the head of the screw rod of the thrust shaft is larger than the size of the through hole of the tool frame. When the dowel assembling and disassembling tool is used for installing the dowel, the dowel is prevented from being stricken in the assembling or disassembling process, and a structural member is protected from damage caused by striking.