A wearable electronic device includes a body and a plug-in power supply. The body is provided with a first battery and a first induction coil or a connecting port electrically connected to the first battery. The plug-in power supply is provided with a carder for wearing the body on a wearer's wrist, at least one second battery disposed in the carder, and a second induction coil or a connector disposed in the carrier or extends outside the carrier and electrically connected to the second battery. The first battery absorbs electric power from the second battery when the second induction coil is coupled to the first induction coil or the connector is connected to the connecting port.