On the basis of using double terminal traveling wave method to carry out on line detection and location of PD of high voltage cable, the time varying kurtosis method used in the field of seismic signal detection is introduced to solve the problem that the precision of the first break time affects the positioning accuracy. Firstly, the PD events is detected by using the method of time window energy ratio, then the pulse arrival time is preliminary picked up by calculating the time varying kurtosis change rate and the maximum point in determining the discharge time window. In order to overcome the influence of strong noise on picking precision, the main frequency band of partial discharge pulse is separated by wavelet packet, and the timevarying kurtosis maximum is obtained in this frequency band, which ensures that the high precision picking up of the first break time of PD pulse is achieved. Finally, the PD source is located by the method of twoterminal traveling wave. The simulation results show that this method can meet the highvoltage power lines on the PD line fault positioning accuracy requirements and effectively improve the reliability of power supply, not only has high precision and strong antiinterference ability, but also can realize that the error is less than 2 m in -14 dB noise environment.