Abstract: A mobile charging module of a wearable electronic device is disclosed. The wearable electronic device includes a main body portion and a lacing portion that can be assembled to or disassembled from the main body portion, wherein the main body portion includes a host, a host battery and a Rx Coil; the lacing portion includes a Tx Coil which can be wireless and inductively charged with the Rx Coil and a backup power supply (BPS); which is characterized in: the Tx Coil and the Rx Coil are mounted on a magnetic body respectively; through controlling a coupling gap between the two magnetic bodies, the magnetic field of the Tx Coil can be coupled to the Rx Coil through the two magnetic bodies for quickly charging the host battery with high efficiency.