Abstract: Method for processing single-phase grounding of non-effectively grounded system comprises: after single-phase grounding occurs, cyclically connecting and disconnecting non-faulted phase or neutral point with ground to form a closed loop together with grounded phase, and repeatedly generating current pulses; using controlled switches (1, 2, 3, 4, 5) to detect current pulses, and setting the number of current pulses triggered to be cut off by controlled switches (4, 5) in downstream of power source direction to be less than the number of current pulses triggered to be cut off by controlled switches (1, 2, 3) in upstream of power source direction; and after one of controlled switches meets trigger condition and is cut off, stopping grounding of non-faulted phase. Single-phase grounded fault point interval is quickly positioned, and fault is removed automatically, quickly and accurately, thereby improving processing quality of single-phase grounded fault and power supply safety.