The utility model relates to a the electricity sector detects the instrument, specifically is a ground connection conduction testing appearance change formula wiring plug, including insulating connection terminal (1), two wiring holes (2) are openly seted up in insulating connection terminal (1), set up in the wiring hole (2) copper thread bush (3), copper thread bush (3) are connected with test wire (4) that are penetrated in the wiring hole (2) by insulating connection terminal (1) the back, installation iron clamping bar (5) is twisted to copper thread bush (3) internal rotation, two iron clamping bar (5) are used for cartridge in band iron (6) edge. The utility model relates to a rationally, the plug adopts the change formula, and the iron clamping bar passes through the helicitic texture and revolves in insulating connection terminal, after clamping bar repetitious usage damages, make new clamping bar can, the insulation connection terminal can reuse, convenient to use is simple, and is pleasing to the eye moreover, has fine practicality and market using value.