The invention discloses a milling clamp tool. The milling clamp tool is used for clamping a composite workpiece needing to be milled to fix the composite workpiece to milling equipment. A first suction part attached to a web plate of the composite workpiece is arranged on a main structure body, multiple second angle-adjustable suction parts used for being attached to the wing edges on the two sides of the composite workpiece are arranged on the two sides of the main structure body, the first suction part and the second suction parts are connected with externally-arranged air exhaust suction equipment, and therefore the web plate and the wing edges on the two sides of the composite workpiece are sucked and fixed to the first suction part and the second suction parts. According to the milling clamp tool, the second suction parts are firmly attached to the wing edges on the two sides of the composite workpiece by adjusting the angle of the second suction parts, and the technical problem that the angle of an existing milling clamp tool is nonadjustable is solved. The milling clamp tool can adapt to various different composite workpieces and is wide in application range.