Abstract: Focus on the semi-conductive buffering layer within high voltage power cables, the deterioration mechanisms of water-blocking semi-conductive buffering tapes, buffering layers and manufacturing process were analyzed, and the risks and cumulative effects of each factor were discussed. Based on the outer screen structure and the interlayer electrical contact pattern within high voltage power cables, the quantification method and realization of electric contact were proposed, and the contact range level of the semi-conductive buffering layer of high voltage power cable was presented. The solution of deterioration factors, simplified risk accumulation mode, and methods for designing and engineering mitigation of semi-conductive buffering layers were summarized.