In the electric vehicle wireless power transfer ( WPT) system, the magnetic shielding effect is often at the expense of transmission efficiency. Reducing magnetic leakage and improving transmission efficiency are the difficult problems. Therefore, a new strong coupling magnetic shielding structure is proposed to reduce the magnetic leakage of the system. Firstly, a strong coupling magnetic shielding coil structure is proposed. Based on the proposed shielding coil structure, the characteristics of system magnetic leakage and transmission efficiency on the impedance of shielding coil are analyzed. Secondly, a magnetic flux leakage optimization method is given. Using the proposed optimization method, the coil parameters that meet the design requirements are obtained. Finally, according to the obtained coil parameters, a wireless charging system based on electric vehicle with magnetic shielding structure is developed. The effectiveness of the proposed structure and method is verified by simulation and experiment. The results show that the proposed new strong coupling magnetic shielding coil not only effectively reduces the magnetic induction intensity of the system by 28%, but also improves the transmission efficiency by nearly 4%.