The invention discloses a connecting bolt enabling a screw to be mounted afterwards and a using method of the connecting bolt. The connection bolt comprises a screw and a rectangular bar. One end of the screw is provided with threads, and the other end is provided with a through notch. The through notch extends to the screw end portion along the direction of an axis of the screw, the rectangular bar is in pin connection onto the screw through a pin shaft in the through notch, and an axis of the pin shaft is vertical to the axis of the screw. The rectangular bar and the geometric center of the pin shaft do not coincide, all or part of the rectangular bar can be placed in the through notch, and the rectangular bar can swing to a position parallel with the axis of the screw or vertical to the axis of the screw around the pin shaft. According to the connecting bolt enabling the screw to be mounted afterwards and the using method of the connecting bolt, the screw is inserted into a bolt hole after two templates are mounted in position and bolt holes are aligned, so that template edges can be fastened; and the screw can be mounted afterwards, so that the fastening mode can be simplified, and the construction progress is fastened.