The invention provides a wireless power receiver which comprises a receiving coil, a rectifier, a voltage detection module and a wireless signal transmitter. The receiving coil is coupled with the transmission coil of a wireless power transmitter to generate alternating induction voltage. The rectifier is electrically connected with the receiving coil and is used for converting the alternating induction voltage into direct current voltage and outputting the direct current voltage to a load. The voltage detection module is connected to the input end of the load and is used for sampling the input voltage signals of the load, so as to judge the changes of the input end voltage of the load and generating a judgment result. The wireless signal transmitter is electrically connected with the voltage detection module and is used for sensing feedback signals to the wireless power transmitter wirelessly according to the judgment result. In addition, the invention also provides the corresponding wireless power transmitter, an electronic device which adopts the wireless power receiver and a wireless power supply method thereof.