Measurement device for surface roughness and measurement workbench for measurement device

The invention provides a measurement device for surface roughness, comprising a measurement mechanism and a measurement workbench, wherein the measurement workbench consists of an upper-layer rack and a lower-layer rack, each layer of the rack comprises a linear guide sliding pair, each linear guide sliding pair comprises a fixed guide rail and an air-floating guide rail, each air-floating guide rail consists of an upper air-floating block, two side air-floating blocks fixedly connected with two sides of the bottom of the upper air-floating block and two bottom air-floating blocks which are fixedly connected with the bottoms of the two side air-floating blocks and oppositely extend respectively, the inner surface of each air-floating guide rail consists of air outlet surface of each air-floating block, air outlet holes are arranged on the air outlet surfaces which are opposite to the fixed guide rails, and the air outlet holes of the air-floating blocks are communicated with one another in the air-floating guide rails by gas passageways and jointly use one air inlet hole; and the invention further provides the measurement workbench. The air-floating guide rails formed into the measurement workbench can move along with the fixed guide rails without friction, so that the problem that the measurement workbench in the prior art is slow in response speed, low in moving speed and low in control precision can be solved.