The invention provides a wireless charging circuit based on an electronic tag. A battery charging circuit is connected with an original tag coil loop; the original tag coil loop generates current in response to an electromagnetic signal of a reading-writing device coil antenna and charges the battery charging circuit; a signal conditioning circuit is connected between the original tag coil loop and the battery charging circuit in parallel, and a radio-frequency signal of the original tag coil loop is converted into a DC signal to be transmitted to the battery charging circuit; the battery charging circuit comprises a voltage stabilizing circuit, a starting switch tube and a charging battery; the voltage stabilizing circuit is connected with the signal conditioning circuit and receives a DCsignal and is used for stabilizing the voltage and providing a starting level; and two non-control ends of the starting switch tube are connected onto a connecting loop of the voltage stabilizing circuit and a charging battery, and when an output level of a starting level output end of the voltage stabilizing circuit reaches a starting level, the starting switch tube is switched on, so that the connecting loop is switched on to charge the charging battery. By adopting the wireless charging circuit, the wireless charging can be conveniently implemented, and the communication interference on the tag coil can be reduced.