In the application of wireless power transfer(WPT) system in the field of electric vehicles, the misalignment of the primary and secondary coils is inevitable, which causes the output power to decrease. In order to the problem, this paper proposed to add a relay coil to the transmission side of double-sided LCC compensated wireless power transfer(WPT) system, thus forming a novel LCC-S-LCC three coil WPT system. Reduce the fluctuation of output power by reducing the sensitivity of mutual inductance between the relay coil and the receive coil to transverse offset distance. Finally, a prototype was built for experimental verification, and the results showed that within the range of transverse offset distances of 30% of the coil size, the output power fluctuation of the novel LCC-S-LCC three coil WPT system was only 5.5%.