Building construction steel structure butt joint device

The utility model discloses a building construction steel structure butt joint device which comprises a chassis, a supporting column arranged in the center of the surface of the top end of the chassis, a mounting groove formed in the surface of the supporting column, a connecting opening formed in the surface of one side of the mounting groove, a supporting plate arranged on the surface of one side of the connecting opening and a limiting plate arranged on the surface of the top end of the supporting plate. A top plate is arranged on the surface of the top end of the supporting column, telescopic devices are arranged on the two sides of the supporting column, and the surface of the bottom end of each telescopic device is fixedly connected with the chassis. By pushing the telescopic pieces upwards, the telescopic pieces drive connecting pieces, the connecting pieces drive telescopic outer columns, and the telescopic outer columns drive mounting grooves to move upwards. The fixing rotary knobs are rotated into