Abstract: When the current method is used to identify the partial discharge events in the cable insulation layer,the partial discharge source cannot be accurately located,resulting in insufficient positioning accuracy of partial discharge. Therefore,this paper proposes a new identification method of partial discharge in the outer protective insulation layer of high-voltage cables in power grids. Partial discharge events are detected by time-window energy ratio,the time-varying kurtosis change rate is calculated to obtain the first arrival time of the pulse,and combined with the time analysis method the location of partial discharge source is completed; the local linear embedding method is used to reduce the dimension of the partial discharge signal to obtain the characteristics of the partial discharge signal, by which the partial discharge identification is completed. The experimental results show that the proposed method has high positioning accuracy, high recognition accuracy and high recognition rate.