To decrease the lightning trip-out rate of transmission line, a new method therefore was put forward to reduce the grounding resistance of transmission tower foundation based on the constant current field theory.This method combined special reinforcing cage with proportional effective anti-corrosion resistance reduction agent to make tower foundation ground tightly,and took up a little space and soil. And all the problems such as reducing grounding resistance by horizontal radial grounding method because of topography were solved.The characteristic of small impulse coefficient and impulse grounding resistance of this device increased the lightning withstand level and power supply reliability of transmission line greatly.Results of instances and practices showed that this method is feasible and validated.
