Embodiments of this application provide a charging method, an electronic device. The electronic device includes one or more universal serial bus USB ports, and the electronic device is connected to a first external device through a first USB port. The method may include: The electronic device and the first external device determine charging power of a first specification based on a first message; the electronic device outputs the charging power of the first specification to the first external device; and when the first external device supports higher charging power, the electronic device outputs charging power of a second specification to the first external device based on a protocol interaction result between the electronic device and the first external device, where the charging power of the second specification includes charging power at a highest charging level that can be received by the first external device.