Three-face clamping device for bar

The invention discloses a three-face clamping device for a bar. The three-face clamping device comprises an operation platform (1), a fixed clamping claw (2), a movable clamping claw (3), an upper clamping claw (4), a moving assembly and a clamping arm assembly. The fixed clamping jaw (2) is fixedly installed on the operation platform (1), the movable clamping jaw (3) is movably installed on the operation platform (1) through a moving assembly, and the fixed clamping jaw (2) and the movable clamping jaw (3) are oppositely arranged. The top of the fixed clamping claw (2) and the top of the movable clamping claw (3) are each of an inclined face structure, so that a V-shaped clamping cavity is formed between the fixed clamping claw (2) and the movable clamping claw (3). The upper clamping claw (4) is rotatably installed on the operation platform (1) through a clamping arm assembly, an inverted-V-shaped clamping cavity is formed in the bottom of the upper clamping claw (4), and the inverted-V-shaped clamping cavi