The invention discloses a high-resistance grounding fault positioning method for a resonant grounding system by using clustering. The method comprises the following steps: judging a high-resistance fault in a line according to a bus zero-sequence voltage and a zero-sequence current signal of each line; extracting zero-sequence current waveforms of different detection points in a first power frequency half-wave time after the fault; performing clustering analysis on the fault current waveforms of different detection points, and dividing all the detection points of the fault line into two detection point groups; and if the distance between the center coordinates of the two point groups is smaller than a threshold value, selecting the last section as a fault section, and otherwise, selectinga boundary section between the two point groups as a fault section. The method for determining the fault section by using the clustering result of the first power frequency half-wave zero-sequence current waveform of the fault is high in applicability and can still be applied when the fault grounding resistance is high; and the polarity and amplitude information of the current measured by all thedetection points on the fault line is integrated for positioning, so that the method has higher reliability and accuracy.