The utility model discloses to adopting current instrument can't satisfy the accurate high -efficient measuring demand of tunnel wall, influence efficiency of construction and construction quality's problem, and then provide a tunnel inner wall height measurement car, which comprises a carriage body, bottom of the car body is provided with the rail wheel, the rail wheel is used for setting up railin the tunnel, automobile body one side is provided with the shallow handle, the fixed extension rule base that is provided with on the automobile body, it is provided with universal spirit level tofix on the extension rule base, be provided with the horizontal plane vertically extension rule with universal spirit level in the extension rule base, the extension rule top is provided with horizontal fixing base, the laser pen along the horizontal direction setting on horizontal fixing base, the fixed spirit level that is provided with on the laser pen. The utility model provides measurement accuracy has been guaranteed to high efficiency of construction, can the wide application in the tunnel elevation positioning of each professional various equipment and pipeline.