The invention discloses a tied arch bridge hanger rod embedded hole centering device which comprises a base supporting a beam upper end face, a mounting platform mounted at the upper end of the base, a laser generating device, a positioning disc and a laser target. The laser generating device, the positioning disc and the laser target are parallel to the lower end face of the base and are arranged on the mounting platform. The invention further discloses a tied arch bridge hanger rod embedded hole centering method. The method includes the following steps: utilizing the centering device to center the laser generating device and hanger rod embedded holes in a lower-portion beam; upwards emitting laser beams, disposing the positioning disc on the lower end face of an arch rib frame, and enabling the laser beams to penetrate laser passing holes in the positioning disc; mounting the laser target on the upper end face of the arch rib frame, and enabling the laser beams to be irradiated to a bull's eye of the laser target to complete centering operation. The tied arch bridge hanger rod embedded hole centering device is simple in structure, convenient to operate, capable of improving centering accuracy of the hanger rod embedded holes and conducive to improving construction efficiency of a tied arch bridge and guaranteeing safety in bridge construction and running.