Provided is a method for preparing a recycled ABS resin, and the method for preparing a recycled ABS resin includes: preparing an extrusion feed including an acrylonitrile butadiene styrene (ABS) base resin including polyurethane, a metal carboxylic acid salt, and a polyhydric alcohol; and supplying the extrusion feed to an extruder to perform a depolymerization reaction of the polyurethane and extruding the extrusion feed.