Abstract: In view of problems of long time consumption and electric leakage of traditional charging modes for mine-used electric locomotive, a wireless charging system for mine-used electric locomotive based on loose coupling transformer was proposed. Effects of iron core matching deviation on loose coupling transformer efficiency were simulated by use of finite element software ANSYS Maxwell, and simulation results were verified through experiments. The simulation and experimental results show that transformer efficiency increases with decrease of air gap, and changes little within 50 mm of transverse displacement deviation and 40 mm of longitudinal displacement deviation.