Abstract: The single capacitive coupled wireless power transfer (SCC-WPT) technology could achieve wireless power transfer, requiring only a pair of the plate. This technology not only could reduce the number of plates but also avoid cross coupling of the coupling structure. It is obvious that the technology has good flexibility in the WPT application of two-dimensional mobile devices. Based on this technology, this paper proposes a three-plate SCC-WPT system, which can transfer power to the two-dimensional mobile devices flexibly. First, by analyzing the equivalent model of the three-plate coupling structure and the effect of the insulating medium on the mutual capacitance between the plates, the equivalent circuit of the controlled voltage source and the resonance condition of the system are studied. Secondly, by combining the coupling capacitance C_M and the mutual capacitance coefficient k_c, the parameter design method of the system is represented. Finally, the experiment verifies the feasibility and effectiveness of the three-plates coupling structure and the parameter design method. The experimental results show that the load can receive ample power at any position on the receiving plate, and the output power keeps stable. Compared with the traditional SCC-WPT system, this paper uses an extra coupling plate to increase the coupling capacitance to the ground, which could overcome the influence of stray capacitance on the system and improve the performance stability and robustness of the system. Meanwhile, this technology can provide a new way for static and dynamic wireless power transfer of two-dimensional mobile devices.