A universal serial bus (USB) interface is used to connect to a USB device. When the driving pole of the USB interface is pressed, the conductive washer of the USB interface is driven to move away from the first terminal and the second terminal of the positive differential signal pin of the USB interface, an electrical connection between the first and second terminals of the positive differential signal pin is cut. When the driving pole is loosed, the conductive washer returns back, to contact the first terminal and the second terminal of the positive differential signal pin, the first and second terminals of the positive differential signal pin are thus electrically connected.