Thickness gauge for rolling mill and running gear of thickness gauge

The invention discloses a running gear of a thickness gauge for a rolling mill. The running gear comprises a rack (1), a gear (2) and a running motor (3), wherein the rack (1) is arranged along the horizontal direction; the gear (2) is meshed with the rack (1); the running motor (3) is used for driving the gear (2); one of the rack (1) and the running motor (3) is fixed on a frame (4) of the rolling machine; and the other one of the rack (1) and the running motor (3) is fixed on the thickness gauge (5) for the rolling mill. In the running gear of the thickness gauge for the rolling mill, a gear rack pair structure consisting of the rack (1) and the gear (2) is used for driving, so the thickness gauge (5) for the rolling mill can run in the horizontal direction, the problem of running instability caused by the cylinder push running mode in the prior art is effectively solved, the running characteristic of the thickness gauge (5) for the rolling mill is optimized, the thickness measuring precision is improved a