A device to be charged, comprising: a battery; a wireless receiving circuit, configured to receive an electromagnetic signal transmitted by a wireless charging device and to convert the electromagnetic signal into an output voltage and an output current of the wireless receiving circuit; a step-down circuit, configured to receive the output voltage of the wireless receiving circuit and perform step-down processing on the output voltage of the wireless receiving circuit, for charging the battery; a detection circuit, configured to detect a voltage and/or a current entering the battery; a control circuit, configured to communicate with the wireless charging device based on the voltage and/or the current detected by the detection circuit, to enable the wireless charging device to adjust a transmitting power of the electromagnetic signal; a first charging channel; and a second charging channel, wherein the control circuit is configured to when a first charging mode is adopted, control the step-down circuit on the first charging channel to operate, and when a second charging mode is adopted, control a conversion circuit on the second charging channel to operate, wherein the conversion circuit is configured to receive the output voltage and the output current of the wireless receiving circuit, and to charge the battery after performing constant voltage and/or constant current control on the output voltage and/or the output current of the wireless receiving circuit, characterized in that the device to be charged is configured to perform bidirectional communication with the wireless charging device to negotiate the charging mode to be adopted. a battery; a wireless receiving circuit, configured to receive an electromagnetic signal transmitted by a wireless charging device and to convert the electromagnetic signal into an output voltage and an output current of the wireless receiving circuit; a step-down circuit, configured to receive the output voltage of the wireless receiving circuit and perform step-down processing on the output voltage of the wireless receiving circuit, for charging the battery; a detection circuit, configured to detect a voltage and/or a current entering the battery; a control circuit, configured to communicate with the wireless charging device based on the voltage and/or the current detected by the detection circuit, to enable the wireless charging device to adjust a transmitting power of the electromagnetic signal; a first charging channel; and a second charging channel, wherein the control circuit is configured to when a first charging mode is adopted, control the step-down circuit on the first charging channel to operate, and when a second charging mode is adopted, control a conversion circuit on the second charging channel to operate, when a first charging mode is adopted, control the step-down circuit on the first charging channel to operate, and when a second charging mode is adopted, control a conversion circuit on the second charging channel to operate, wherein the conversion circuit is configured to receive the output voltage and the output current of the wireless receiving circuit, and to charge the battery after performing constant voltage and/or constant current control on the output voltage and/or the output current of the wireless receiving circuit, characterized in that the device to be charged is configured to perform bidirectional communication with the wireless charging device to negotiate the charging mode to be adopted.