A wireless charging receiving device, wireless charging method and system, and terminal device are provided. The device includes a control unit, receiving coil, rectifier-filter unit, first voltage conversion unit and battery cell module. The control unit transmits a first control signal to a wireless charging transmitting device and outputs a second control signal to the first voltage conversion unit if the wireless charging transmitting device is of a model belonging to a first preset model set and an output voltage of the battery cell module is within a preset range. The receiving coil senses a first electromagnetic wave to generate a first AC. The rectifier-filter unit converts the first AC into a first DC. The first voltage conversion unit converts the first DC into a second DC under the control of the second control signal. The battery cell module is charged by the second DC.