Transmission line tower as the normal operation of the power system of the necessary equipment，its grounding resistance accurate detection for the safe and stable operation of the entire power system is particularly important，especially in the judgment of lightning protection performance and other aspects. Thus，a multi-frequency tower grounding resistance measurement method was proposed based on radial basis function （RBF） fitting. The method was able to use multi-frequency current as an excitation under the premise of not disconnecting the tower grounding lead，measure the grounding resistance value obtained from the input current of different frequencies，and then use radial basis function neural network fitting based on these data to realize the accurate measurement of the tower grounding resistance. At the same time，the accuracy and reliability of the method was proved through the measurement of grounding resistance of multiple towers，and the proposed method is simple to operate，which largely facilitates the measurement of inspectors on the spot，and has strong practical significance.

tower  /  grounding resistance  /  radial basis function（RBF）