The utility model provides an american case of 10kV becomes special plug instrument of high -voltage testing. Safe distance is not enough, the problem of wiring complicacy for the high -pressure side mechanism that solves the change of the american case of 10kV appears when the handing -over is checked and accepted. A terminal and no. Two terminals are cylindrically, the one end of no. Two terminals is fixed on the lateral wall of a terminal, insulating sheath is hollow cylinder, the nested middle part at no. Two terminals of insulating sheath, it has a plurality of wiring through -holes to open on the side of a terminal, and a plurality of wiring bolts are located a terminal lateral wall of a plurality of wiring through -hole departments respectively to the axle center of wiring through -hole with work a telephone switchboard that the bolt is perpendicular to be set up. The beneficial effects of the utility model are that the wiring is convenient, and is simple, the safe distance of wiring has been increased. Not only save wiring time but also guaranteed the security of wiring, reduced the potential safety hazard, reduced the wiring error, improved work efficiency. The utility model is suitable for a high -pressure side wiring that the american case of 10kV becomes is experimental.