A wireless charging circuit, comprising an oscillation circuit and a monitoring circuit that are sequentially connected, wherein the oscillation circuit comprises an excitation voltage source, a full-bridge circuit, and an LC series circuit that are connected in series, wherein the excitation voltage source is configured to provide a stable voltage for the LC series circuit; the full-bridge circuit comprises a first bridge arm and a second bridge arm that are connected in parallel, the first bridge arm comprises a first switching transistor Q1 and a third switching transistor Q3, and the second bridge arm comprises a second switching transistor Q2 and a fourth switching transistor Q4; the LC series circuit comprises an inductor and a resonance capacitor that are connected in series, one terminal of the LC series circuit is connected to a phase midpoint of the first bridge arm, and the other terminal is connected to a phase midpoint of the second bridge arm; and a phase midpoint of the LC series circuit is connected to the monitoring circuit, and is configured to output a resonant voltage signal during damped oscillation to the monitoring circuit; the monitoring circuit comprises a comparison module and a processing module; the comparison module is configured to receive the resonant voltage signal, and convert the resonant voltage signal into a digital square wave signal; the processing module is configured to: receive the digital square wave signal, obtain a resonant voltage attenuation waveform during damped oscillation based on turn-on and turn-off of the switching transistors Q1 to Q4, obtain a first parameter that meets a first preset condition and that is in the resonant voltage attenuation waveform, determine a quality factor Q based on the first parameter, and monitor a foreign object based on the quality factor Q to obtain a monitoring result, wherein the first parameter comprises a quantity of peaks, a quantity of troughs, or a sum of the quantity of peaks and the quantity of troughs, and the quality factor Q represents a ratio of power stored in the oscillation circuit to a power loss in each cycle; wherein the first preset condition is that in each oscillation cycle, a resonant voltage generated during damped oscillation is greater than a reference voltage; and when a voltage of the phase midpoint of the LC series circuit to ground reaches an amplitude voltage of the excitation voltage source, the damped oscillation occurs in the oscillation circuit to generate the resonant voltage. the oscillation circuit comprises an excitation voltage source, a full-bridge circuit, and an LC series circuit that are connected in series, wherein the excitation voltage source is configured to provide a stable voltage for the LC series circuit; the full-bridge circuit comprises a first bridge arm and a second bridge arm that are connected in parallel, the first bridge arm comprises a first switching transistor Q1 and a third switching transistor Q3, and the second bridge arm comprises a second switching transistor Q2 and a fourth switching transistor Q4; the LC series circuit comprises an inductor and a resonance capacitor that are connected in series, one terminal of the LC series circuit is connected to a phase midpoint of the first bridge arm, and the other terminal is connected to a phase midpoint of the second bridge arm; and a phase midpoint of the LC series circuit is connected to the monitoring circuit, and is configured to output a resonant voltage signal during damped oscillation to the monitoring circuit; the monitoring circuit comprises a comparison module and a processing module; the comparison module is configured to receive the resonant voltage signal, and convert the resonant voltage signal into a digital square wave signal; the processing module is configured to: receive the digital square wave signal, obtain a resonant voltage attenuation waveform during damped oscillation based on turn-on and turn-off of the switching transistors Q1 to Q4, obtain a first parameter that meets a first preset condition and that is in the resonant voltage attenuation waveform, determine a quality factor Q based on the first parameter, and monitor a foreign object based on the quality factor Q to obtain a monitoring result, wherein the first parameter comprises a quantity of peaks, a quantity of troughs, or a sum of the quantity of peaks and the quantity of troughs, and the quality factor Q represents a ratio of power stored in the oscillation circuit to a power loss in each cycle; wherein the first preset condition is that in each oscillation cycle, a resonant voltage generated during damped oscillation is greater than a reference voltage; and when a voltage of the phase midpoint of the LC series circuit to ground reaches an amplitude voltage of the excitation voltage source, the damped oscillation occurs in the oscillation circuit to generate the resonant voltage.