An electronic apparatus includes a first component and a second component. The first component is configured to connect to a processing device containing a power storage module, and the second component is configured to connect to an extension device. In a first state, the electronic apparatus connects to the processing device and the expansion device. An external power supply provides power to the processing device through the first component, and provides power to the expansion device. In a second state, the electronic apparatus connects to the processing device and the expansion device. In response to the external power supply being cut off, power is supplied to the expansion device through the second component. The processing device is powered by its power storage module. After the electronic apparatus switches from the first state to the second state, the connection state of the expansion device and the processing device is capable of being maintained.