The invention discloses a five-claw elastic pneumatic clamping device for a turning and grinding machine tool, which comprises: a piston body, on which a piston rod is slidably connected; a cylinder assembly, which includes a self-locking cylinder shaft, a cylinder body and a cylinder head, The self-locking cylinder shaft, cylinder body and cylinder head are all located inside the piston body, one end of the cylinder body is fixed on one end of the self-locking cylinder shaft, and the cylinder head is fixed on the other end of the cylinder body; the clamping assembly includes special-shaped five Claws and V-shaped positioning block, one side wall of the V-shaped positioning block is set on the other end of the self-locking cylinder shaft, the special-shaped five-claw is set on the other side wall of the V-shaped positioning block, and the special-shaped five-claw, V-shaped positioning block It is connected with the self-locking cylinder shaft in sequence through bolts; the compression spring assembly, the compression spring assembly includes a compression spring seat, a compression spring positioning sleeve and a rectangular compression spring, and the compression spring seat and the compression spring positioning sleeve are arranged oppositely, and the rectangular compression spring is located on the two between. The clamping device has good structure compactness, good clamping consistency, safe and reliable clamping, and strong controllability of adjustment precision.