Abstract: Through the analysis of each electrical characteristic quantity of single-phase grounding fault in the small resistance grounding system of the distribution network, the problems of low power supply reliability, zero sequence protection rejection and failure section positioning in the case of high resistance grounding fault caused by the failure nature of the small resistance grounding system are discussed. A method of single-phase grounding fault treatment and section location of small resistance grounding system based on intelligent resistance grounding equipment and node zero sequence current amplitude comparison model is proposed. The fault is identified and handled by the method of multi electric characteristic quantity correlation and start-up, and the instantaneous fault is quickly recovered by the method of differential delay, which improves the reliability of power supply. When a permanent ground fault occurs, the intelligent resistance grounding device reports a fault line selection message to the distribution automation main station, the distribution automation terminal in the fault feeder obtains the zero sequence current value of each node, and a section positioning judgment based on the node zero sequence current comparison method is constructed to realize the fault section positioning. Using MATLAB/Simulink simulation environment, the grounding fault area location model of distribution network grounded by intelligent resistance is built. This method can determine the parameter characteristics of upstream and downstream fault and section effectivety. It provides an an effective solution to solve the problem of intelligent processing of single-phaes grounding fault in small resistance grounding system of distribution network.