A wireless charging circuit applicable to a stylus, wherein the wireless charging circuit comprises a first coil, a chip (1301, 1601), and a first battery, wherein the first coil is configured to be coupled to a second coil to obtain an alternating current signal; the chip (1301, 1601) comprises a rectifier (1001, 1201), a charger unit, a micro-control unit, and a protocol encoding/decoding unit (1004, 1204), and is configured to charge the first battery based on the alternating current signal; the rectifier (1001, 1201) is configured to rectify an input alternating current signal into a direct current signal; the charger unit comprises a voltage-stabilizing charging circuit and is configured to charge the first battery by using the direct current signal from the rectifier (1001, 1201), wherein the voltage-stabilizing charging circuit comprises a first field effect transistor control module, a first field effect transistor, and a second field effect transistor, wherein a gate terminal of the first field effect transistor and a gate terminal of the second field effect transistor are both connected to the first field effect transistor control module, and the first field effect transistor control module is configured to control a voltage value of the gate terminal of the first field effect transistor and a voltage value of the gate terminal of the second field effect transistor, a source terminal of the first field effect transistor is connected to an output terminal of the rectifier (1001, 1201), a drain terminal of the first field effect transistor is connected to a source terminal of the second field effect transistor, and a drain terminal of the second field effect transistor is used to charge a battery of the stylus, wherein the first field effect transistor is a MOSFET and is configured to stabilize a voltage output by the rectifier (1001, 1201) and wherein the second field effect transistor is a MOSFET and is configured to isolate a system power supply of the chip from the first battery; the protocol encoding/decoding unit (1004, 1204) is configured to communicate with a transmit chip; and the micro-control unit is configured to control the charger unit and the protocol encoding/decoding unit (1004, 1204). to a stylus, wherein the wireless charging circuit comprises a first coil, a chip (1301, 1601), and a first battery, wherein the first coil is configured to be coupled to a second coil to obtain an alternating current signal; the chip (1301, 1601) comprises a rectifier (1001, 1201), a charger unit, a micro-control unit, and a protocol encoding/decoding unit (1004, 1204), and is configured to charge the first battery based on the alternating current signal; the rectifier (1001, 1201) is configured to rectify an input alternating current signal into a direct current signal; the charger unit comprises a voltage-stabilizing charging circuit and is configured to charge the first battery by using the direct current signal from the rectifier (1001, 1201), wherein the voltage-stabilizing charging circuit comprises a first field effect transistor control module, a first field effect transistor, and a second field effect transistor, wherein a gate terminal of the first field effect transistor and a gate terminal of the second field effect transistor are both connected to the first field effect transistor control module, and the first field effect transistor control module is configured to control a voltage value of the gate terminal of the first field effect transistor and a voltage value of the gate terminal of the second field effect transistor, a source terminal of the first field effect transistor is connected to an output terminal of the rectifier (1001, 1201), a drain terminal of the first field effect transistor is connected to a source terminal of the second field effect transistor, and a drain terminal of the second field effect transistor is used to charge a battery of the stylus, wherein the first field effect transistor is a MOSFET and is configured to stabilize a voltage output by the rectifier (1001, 1201) and wherein the second field effect transistor is a MOSFET and is configured to isolate a system power supply of the chip from the first battery; wherein a gate terminal of the first field effect transistor and a gate terminal of the second field effect transistor are both connected to the first field effect transistor control module, and the first field effect transistor control module is configured to control a voltage value of the gate terminal of the first field effect transistor and a voltage value of the gate terminal of the second field effect transistor, a source terminal of the first field effect transistor is connected to an output terminal of the rectifier (1001, 1201), a drain terminal of the first field effect transistor is connected to a source terminal of the second field effect transistor, and a drain terminal of the second field effect transistor is used to charge a battery of the stylus, wherein the first field effect transistor is a MOSFET and is configured to stabilize a voltage output by the rectifier (1001, 1201) and wherein the second field effect transistor is a MOSFET and is configured to isolate a system power supply of the chip from the first battery; the protocol encoding/decoding unit (1004, 1204) is configured to communicate with a transmit chip; and the micro-control unit is configured to control the charger unit and the protocol encoding/decoding unit (1004, 1204).