Abstract: Special bolts for grounding downlead of transmission tower developed in this paper. The grounding resistance can be measured without dismantling the grounding downlead. The utility model can avoid personal injury caused by popping when the grounding downlead is disassembled, and the safety during measurement is improved. At the same time, it ensures that the grounding down lead can be connected to the fixed plate of the tower again after measuring the grounding resistance. The workload of maintenance is reduced and the work efficiency is improved. It reduces the physical consumption of operators and ensures personal safety.