The present invention relates to a power plug assembly, includes: a cable having two power wires; a lighting unit, the center of the lighting unit is provided with a ring-shaped hole for being connected onto the cable, and the lighting unit is disposed behind the two power wires, the lighting unit is composed by a ring-shaped housing and a ring-shaped printed circuit board provided in front of the ring-shaped housing, a plurality of light sources connected in parallel via wires are provided in the housing, and the front end of the housing is provided with two power input terminals for being coupled with the printed circuit board, two guiding wires are extendedly provided on the front end of the printed circuit board; a conductive tube having an outer tube and an inner tube, an insulating material is provided between the outer tube and the inner tube, with respect to the polarity, the two power wires and the two guiding wires are respectively provided on the outer tube and the inner tube, then a welding operation is processed so as to fasten the two power wires and the two guiding wires on the conductive tube; and an outer covering member made by an operation of plastic injection and served to cover the rear portion of the conductive tube, the front portion of the cable and the lighting unit, and the ring-shaped housing is exposed out of the outer covering member.