A power adapter includes an adapter main body configured to acquire an alternating current from a power source and convert the alternating current into a direct current having a specified voltage; an output port configured to acquire the direct current from the adapter main body, and supply the direct current to an external device via the positive output port and the negative output port; a current divider arranged between the positive output port and the negative output port, and configured to split the direct current from the adapter main body upon receiving a control signal, so as to cause a value of an output voltage output through the positive output port and the negative output port to be less than or equal to a preset value; and a processor configured to transmit the control signal to the current divider.