A welding rotatable work fixture for an automobile front bumper beam sub assembly comprises a base (1). The right side of the base (1) is provided with a tilt motor (2) and a speed reducing case (15), and the left side of the base (1) is provided with a turnover board assembly (4). The welding rotatable work fixture is characterized in that a six-directional adjusting main positioning mechanism (5), a left side face compression air cylinder mechanism (6), a six-directional adjusting auxiliary positioning mechanism (7), a right side face compression air cylinder mechanism (8), a front face compression air cylinder mechanism (9), compression pliers (11) and a material supporting air cylinder mechanism (12) are inflated with air and tightly press the automobile front bumper beam sub assembly, a foot switch (3) controls the tilt motor (2) to rotate, the turnover board assembly (4) rotates by 0-270 degrees according to the welding position, and the welding position is carried out. By means of the welding rotatable work fixture, the machining efficiency can be improved manyfold, the speed is high, the benefits are high, the labor intensity is reduced, and the quality of machined products is good.