An adjustable USB female connector includes a metal top shell, an insulated main body with connection pins which are compatible with USB interface protocol, and a metal bottom shell. The connection pins are fixed on the insulated main body. The insulated main body is fastened in the metal top shell. The metal top shell is slidably connected to the metal bottom shell, and the total thickness of the metal top shell and the metal bottom shell is variant. In a first orientation, the thickness of the USB female connector is the smallest, and the thickness is smaller than that of the standard USB female connector. In a second orientation, the metal bottom shell is pulled out, the thickness of the USB female connector increases and reaches the thickness of the standard USB female connector.