Abstract: In order to comprehensively study influence factors such as grounding resistance, line resistance, fault location, grounding capacitance, interphase capacitance and arc ignition time on arc grounding over-voltage in mine power supply system, typical mine power supply system model and intermittent arc grounding model were built by using real time digital simulator, based on arc extinction theory of power frequency and arc extinction theory of high frequency, formation process and influencing factors of arc grounding over-voltage were analyzed theoretically, and the influencing factors were simulated. The simulation results show that arc ignition time has the most significant influence on arc grounding over-voltage, line resistance, grounding resistance and interphase capacitance have great influence, fault location and earth capacitance have small influence; arc grounding overvoltage is a comprehensive reflection of system parameters, and the overvoltage values of different power supply systems in mines vary greatly.