Fault location for stator single-phase ground fault can extend the function of stator ground fault protection, providing a reference for fast detecting the fault. The paper analyses the potential characteristics of the large turbine generator, deduces the relation between the stator winding potential fault position, and gives a new formula of winding potential. The characteristics of zero sequence voltage and three phase voltage are analyzed when stator single-phase ground fault is occurring, and the relation between three-phase voltage amplitude and fault position & grounding resistance is deduced. Therefore, a new fault location principle based on the amplitude of zero sequence voltage and three-phase voltage is proposed. The theoretical analysis and simulation show that this method can detect the fault location reliably. In addition, it is immune no matter which neutral grounding mode is used. The fault location scheme only uses zero sequence voltage and three phase voltage, is very simple, don’t need additional equipment, and can be used to detect high impedance grounding fault. The simulation shows that it is feasible. This work is supported by Fundamental Research Funds for the Central Universities (No. 2016MS87).