Abstract: The paper introduced principle of connection, measuring principle and selection of measuring voltage of three-pole measurement method of grounding resistance of arrester, established a trend prediction model of grounding resistance based on regression analysis according to measured history data of grounding resistance, and proved the model can be used to predict actual grounding resistance by standard deviation testing. The practice showed that the methods of measurement and prediction are practical and feasible, which can avoid lightning strokes caused by over standard of grounding resistance in a way.