Aiming at the problem of arc suppression and protection of single-phase grounding fault in non effectively grounded distribution network, a single-phase grounding fault arc suppression method based on line voltage combination regulation of distribution network is proposed. Using the characteristics of single-phase grounding fault and line voltage constant in the regulation process, the three-phase line voltage is obtained from the adjustable injection transformer from the system, the injection transformer ratio and the secondary side switch are adjusted to flexibly regulate the zero sequence voltage, and the fault phase voltage is actively suppressed to 0, which realizes reliable arc suppression of grounding fault. Furthermore, a single-phase grounding fault type and feeder identification method based on the combined regulation of line voltage in distribution network is proposed. The change characteristics of injection current, zero sequence voltage and zero sequence current of each feeder before and after the change of injection transformation ratio are analyzed. The double identification criteria of ground fault type and feeder based on phase angle difference and admittance ratio are constructed to realize the sensitive identification of ground fault type and fault feeder. The proposed method is verified in PSCAD/EMTDC simulation environment. The simulation results show that the method can effectively suppress the grounding fault arc, realize the active, sensitive and accurate identification of grounding fault types and feeders, and improve the safe and reliable operation ability of distribution network.