Ground flatness measuring instrument

The utility model discloses a ground flatness measuring instrument which comprises a horizontal plate, a horizontal ruler located in the center of the horizontal plate and a plurality of distance measuring lamps distributed on the periphery of the horizontal ruler in a central symmetry mode, the distance measuring lamps are vertically arranged at the bottom of the horizontal plate, a plurality of threaded cylinders are vertically arranged on the periphery of the horizontal plate, and the threaded cylinders are connected with the horizontal plate. And a plurality of supporting rods with threads are in threaded connection with the plurality of threaded cylinders in a one-to-one correspondence manner. The measuring instrument can be used for measuring ground flatness, directly reading data of relative height difference, adjusting the length of the supporting rod, enabling the circular leveling instrument to be horizontally centered, pressing a remote controller or a manual input plate to measure the distance bet