A wireless power supply device and method applied to an electronic lock is implemented between a power supply unit and a power receiving unit. The power supply unit is connected to an external power source and has a first radio frequency coil and a first wireless communication module. The power receiving unit is connected to an electronic lock and has a second radio frequency coil and a second wireless communication module. When the power supply unit wirelessly transmits the power provided by the external power source to the power receiving unit, the power receiving unit and the power supply unit perform a handshaking process to confirm whether they are paired objects, if yes, the power is allowed to be transmitted to the electronic lock, so that the security of wireless power supply can be improved.