Wireless Power Transfer (WPT) technology can transfer energy without direct cable connection, and can avoid sparks caused by the insertion and removal of metal plugs. It is suitable for underwater equipment charging, implantable medical equipment, consumer electronics and Electric vehicles, etc. In view of the above problems, this paper proposes a S/T compensation topology with constant output capability under the condition of wide load and variable coupling. The relationship between output current/voltage gains and S/T topology's parameters as well as coupling coefficient and load is established. A non-resonant compensation parameter design method is given and the advantages and disadvantages of it. The possibility of realizing soft switching of the inverter under full working conditions is discussed. This paper discusses the way to achieve CC/CV switching on the secondary side by changing the topological branch parameters. The optimized phase-controlled capacitor (Switch-Controlled-Capacitor, SCC) and AC switch are used in the secondary side to realize CC/CV switching. The principle and optimization scheme of SCC are given.