Abstract: An automobile steering wheel locking device includes a bar element and a locking portion disposed to one end of the bar element, the locking portion including a base in which an alarm device is disposed, a tube rotatably and transversely disposed through the base wherein a hole and an actuating portion are respectively defined in the tube, a covered-up portion extending radially from each one of two ends of the tube wherein each one of the two ends extends from the base so as to receive a section of the steering wheel within a space defined by the base, the covered-up portions and a plate extending from the bar element, a lock disposed to the bar element and having a pin controllably inserted into the hole and an actuating rod extending from the alarm device connected to the actuating portion of the tube such that when the pin is moved from the hole of the tube by operating the lock, the tube is then rotated by the fact that the covered-up portions drop downwardly by the gravity and the actuating rod of the a