Embedded plug pin device of fabricated staircase and construction method of embedded plug pin device

The invention provides an embedded bolt device of an assembly type stair and a construction method of the embedded bolt device, the embedded bolt device comprises an embedded nut, a bolt and a plugging nut, the embedded nut is fixedly arranged on the lower surface of a surface layer template for pouring a stair beam in advance, and then after the stair beam is formed through pouring and the prefabricated stair is hoisted to the stair beam, the plugging nut is plugged into the bolt. The plug pin penetrates through the plug-in cavity in the end of the prefabricated stair and then is in threaded connection with the embedded nut, and finally the plugging nut is in threaded connection with the end of the plug pin so that an opening of the plug-in cavity of the prefabricated stair can be plugged. Therefore, according to the technical scheme, the prefabricated staircase and the staircase beam are connected through the two-section type embedded bolt device, so that the anchoring capacity between the prefabricated sta