A USB circuit, applicable to the technical field of electronics. The USB circuit comprises a USB connecting piece (10), a first USB contact piece (20), a second USB contact piece (30), and a switching circuit (40). The first USB contact piece (20) is disposed on one surface of the USB connecting piece (10). The second USB contact piece (20) is disposed on the other surface of the USB connecting piece (10) opposite to the first USB contact piece (20). The switching circuit (40) is electrically connected to the first USB contact piece (20) and the second USB contact piece (30), and the switching circuit (40) is configured to switch between conducting the first USB contact piece (20) and conducting the second USB contact piece (30). Also provided is a terminal. By providing the switching circuit (40) to switch between conducting the first USB contact piece (20) and conducting the second USB contact piece (30), the USB circuit can operate while enabling a reversible insertion connection of the USB connecting piec
