As an important facility for peak shaving and frequency modulation, the operation safety of pumped storage unit is of great significance for power systems to accommodate new energy power generation. Focusing on stator grounding fault, which have the highest occurrence probability, this paper proposes a fault location method and a multi-solution countermeasure suitable for the winding configuration and parameter characteristics of pumped storage units. Based on the analysis of the fault equivalent circuit, a fault location approach based on the intersection of phasor trajectory is proposed. Combined with a winding potential calculation method based on slot potential analysis, the causes of multiple solutions in fault location results are analyzed and summarized. By introducing injection information or triple harmonic voltage information as auxiliary information, the multi-solution screening is achieved, enabling the determination of a unique fault location. Finally, the effectiveness of the proposed location method is verified by simulation and experimental analysis.