Abstract: The frequency bifurcation occurs in the magnetic coupling wireless charging system under the condition of over coupling, which leads to a significant reduction in the system performance of the frequency resonant point. In view of the frequency bifurcation phenomenon in wireless charging system, most of the existing literatures are based on the basic topology such as SS structure, and lack of research on the frequency bifurcation phenomenon of complex resonant structures such as S-LCL. Therefore, the frequency bifurcation of dual-load magnetic resonance S-LCL wireless charging system is studied. Firstly, the variation of output characteristics and system efficiency of dual-load system with operating frequency is analyzed. Secondly, the conditions under which the dual-load system can avoid the frequency bifurcation phenomenon and the expression of the bifurcated resonant frequency are derived by using the impedance characteristics at the resonant frequency. The influence of coupling coefficient and load resistance on the frequency bifurcation critical point and output characteristics of the dual-load magnetic resonance S-LCL wireless charging system is simulated and analyzed, and the value range of the load and coupling coefficient to avoid the frequency bifurcation phenomenon is obtained. Finally, Matlab simulation model and physical platform are built to verify the conclusions obtained.