A power supply device includes a first body and a second body. The first body has an opening and an adapter module which is electrically connected to a first electronic device. The opening is divided into a first part and a second part via a first axis, and the shape of the first part is asymmetrical to the shape of the second part. The second body has an energy storage unit. The energy storage unit is electrically connected to the adapter module to supply power to the first electronic device, when the second body is detached from the first body, the energy storage unit is adapted to supply power to a second electronic device.