A controlling method and device for a wireless power transfer system, wherein the wireless power transfer system includes a transmitting component and a receiving component, and further includes a contactless transformer & compensation (CT&C) circuit, and the controlling method includes: obtaining positional relationship information of the transmitting component and the receiving component; adjusting the number of coil turns of the transmitting component based on the positional relationship information, and making conditions of a CT&C voltage gain characteristic and an input impedance characteristic after a charging inverter bridge of the wireless power transfer system meet a charging condition. The abovementioned technical solution can provide a protection for a stable operation of the wireless power transfer system with a non-mechanical adjusting device, and the wireless charging can be achieved without using a mechanical adjusting device to align and range.