Abstract: Entering the equal-potential is a key step of live working on UHV transmission lines, while the characteristic parameters of the pulse waveform of the potential transfer current are the basis for the determination of its equivalent circuit, arc energy and electromagnetic interference characteristics. Taking the measured data of the potential transfer current of 1000kV AC transmission line as a sample, this paper extracts the statistical characteristic quantities of the algorithm through the waveform parameters and analyzes the size and distribution of the attenuated oscillation pulse waveform parameters. By using the maximum likelihood method the characteristic distribution equation parameters are estimated. Combining the electromagnetic analysis software and the characteristic parameters the parameters of the weakly damped second-order loop components of the potential transfer are calculated. The results show: the amplitudes of the discharge pulse are mainly distributed in −300, 300A, and the probability density obeys the distribution of Generalized Extream Value; the main frequencies of its oscillation are distributed in the frequency band range of 1.11, 25 MHz, and the average rise time is 0.020 4μs, which is easy to produce strong electromagnetic pulse interference; the waveform attenuation constant interval is in 0.004, 0.989. The simulated waveforms produced by the potential transfer equivalent circuit element parameters is mostly consistent with the actual waveforms. The research results will provide a basis and method for the selection of characteristic parameters of the potential transfer pulse and energy calculation.