Abstract: The ultra-fast transient over-voltage(VFTO) has the characteristics of high amplitude, steep wavefront, long frequency band and long duration. The rated voltage determines the damage degree of VFTO to the equipment, and it also seriously threatens the safety of gas insulated switchgear(GIS) and neighboring power equipment. Finding effective inhibitory measures is extremely important. There are several measures that have inhibitory effects, but there are corresponding defects. A design method for high frequency overvoltage suppression wires is presented, namely damping bus bars. Under the power frequency, the insulation performance and flow capacity of the busbar do not affect the performance, but when the frequency is high, the traveling wave current forms a high voltage at the inductor end. The traveling wave energy is absorbed by the damping resistor at both ends under the action of high voltage, which inhibits VFTO.