Workbench of CNC (computer numerical control) machine tool

The utility model discloses a CNC numerical control machine tool workbench which comprises a workbench body, a plurality of positioning pieces, a negative pressure device and a control unit, first grooves which are perpendicular to each other are evenly distributed in the surface of the workbench body in the transverse direction and the longitudinal direction, scale marks are arranged on the edge of the workbench body, and the negative pressure device is arranged in the first grooves. A plurality of blind holes and air exhaust holes are formed in the workbench body, the positioning pieces are movably arranged at the blind holes, and the negative pressure device is connected with the air exhaust holes through a high-pressure pipeline; the working table further comprises a plurality of sealing rings, the sealing rings are movably arranged at the first grooves, and the negative pressure device is used for providing negative pressure for a closed area formed by the working table body, the sealing rings and a work