Online measurement method and device for grounding resistor of rod tower

The invention provides an online measurement method and device for a grounding resistor. By using a meter clamping method, four pairs of potential transformers PT and current transformers CT are respectively connected on two anti-lightning wires at the left end and the right end of a rod tower. Voltage signals are sensed to the anti-lightning wires through the potential transformers; current signals are collected and measured, and the current signals are subjected to signal processing steps such as filtering and amplifying to obtain relation of feedback current and inductive voltage; and finally, the resistance of the grounding resistor of the rod tower to be measured is obtained by a special calculation method. With the adoption of the online measurement method and device, data measurement is carried out on the top of the rod tower. The online measurement method and device can be suitable for the rod tower containing a plurality of down leads, so that the anti-theft problem can be solved, and the grounding resistor can be rapidly and accurately measured.