Abstract: Given that the conventional wireless power transmission system using a flat coil structure is not suitable for the energy transmission of trains during operation, a coupling structure of an E shaped iron core coil for RX (receiving end) is designed to meet the dynamic requirements of rail transit power supply system. Comprehensively considering the deviation of vehicle parking, the horizontal and vertical clearances and the allowable installation volume on the train, a dynamic resonant coil coupling model is established, and the variable factors of the resonant status are analyzed, including self inductance, coil mutual inductance and coupling capacitance. Considering the actual requirements of engineering applications, the structural parameters of RX and TX (transmitting end) are designed. The E shaped iron core coil is simulated to verify its influence on coupling coefficient in different situations, such as an offset in x axis (line transverse) positive direction, a small range offset in y axis (line longitudinal) positive direction, a large range offset in y axis negative direction, and offset to the limit position. The results show that the E shaped iron core coil in the x axis direction has almost no effect on coupling parameters such as self inductance and mutual inductance. Except when the coil structure is offset to the limit position, the coupling coefficient of E shaped iron core coil remains relatively stable. The model can effectively reduce the impact of coupling coefficient changes on wireless power transmission system stability.