An adapter comprising: an input port, a first output port and a second output port; a rectifier circuit having an input terminal being connected to the input port of the adapter; a bus capacitor connected to an output terminal of the rectifier circuit in parallel; a first flyback converter having an input terminal connected to the bus capacitor and an output terminal coupled to the first output port; a second flyback converter having an input terminal connected to the bus capacitor and an output terminal coupled to the second output port; a first main control unit and a first output control unit; and a second main control unit and a second output control unit; wherein the first flyback converter is connected with the first output port through a first switch, and the second flyback converter is connected with the second output port through a second switch; wherein the first main control unit is configured to control the first flyback converter, the first output control unit is configured to control the first switch, the second main control unit is configured to control the second flyback converter, and the second output control unit is configured to control the second switch; wherein the first output control unit is configured to receive a first load signal, and set a first output voltage reference according to the first load signal; and the second output control unit is configured to receive a second load signal, and set a second output voltage reference according to the second load signal; wherein the first output control unit is configured to detect a first output voltage of the first flyback converter, and generate a first feedback signal according to the first output voltage reference and the first output voltage; the second output control unit is configured to detect a second output voltage of the second flyback converter, and generate a second feedback signal according to the second output voltage reference and the second output voltage; the first main control unit is configured to receive the first feedback signal, and generate a first driving signal according to the first feedback signal to control the first flyback converter; and the second main control unit is configured to receive the second feedback signal, and generate a second driving signal according to the second feedback signal to control the second flyback converter. an input port, a first output port and a second output port; a rectifier circuit having an input terminal being connected to the input port of the adapter; a bus capacitor connected to an output terminal of the rectifier circuit in parallel; a first flyback converter having an input terminal connected to the bus capacitor and an output terminal coupled to the first output port; a second flyback converter having an input terminal connected to the bus capacitor and an output terminal coupled to the second output port; a first main control unit and a first output control unit; and a second main control unit and a second output control unit; wherein the first flyback converter is connected with the first output port through a first switch, and the second flyback converter is connected with the second output port through a second switch; wherein the first main control unit is configured to control the first flyback converter, the first output control unit is configured to control the first switch, the second main control unit is configured to control the second flyback converter, and the second output control unit is configured to control the second switch; wherein the first output control unit is configured to receive a first load signal, and set a first output voltage reference according to the first load signal; and the second output control unit is configured to receive a second load signal, and set a second output voltage reference according to the second load signal; wherein the first output control unit is configured to detect a first output voltage of the first flyback converter, and generate a first feedback signal according to the first output voltage reference and the first output voltage; the second output control unit is configured to detect a second output voltage of the second flyback converter, and generate a second feedback signal according to the second output voltage reference and the second output voltage; the first main control unit is configured to receive the first feedback signal, and generate a first driving signal according to the first feedback signal to control the first flyback converter; and the second main control unit is configured to receive the second feedback signal, and generate a second driving signal according to the second feedback signal to control the second flyback converter.