Disclosed is a charging method of a multi-node wireless charging system using magnetic field communication capable of effectively charging a plurality of nodes using the magnetic field communication. The magnetic field communication protocol for wireless charging is prepared and thus, an appropriate wireless charging device may be selected and charged for an appropriate time. The wireless charging method of the present invention includes: transmitting an association request frame; receiving an association response frame from the wireless charging devices; transmitting a charging requirement request frame; receiving a charging requirement response frame from the wireless charging devices; transmitting a charging preparation request frame; and transmitting power during a receiving period of the charging preparation response frame for the charging preparation request frame.