The utility model discloses a road construction road bed measuring apparatu, including measuring stick, base, washing cover and plug, the measuring stick top is connected with the press, and is fixed with the manometer above the press, base top is fixed with the rectangle chalk, and rectangle chalk right side installs the spout, wash the cover left side and be connected with the gage beam, and wash the inside brush that is provided with of cover, the inside dead lever that passes through of slip cap is connected with the gage beam, and is connected with the base through the spout below the dead lever, the spout is inside to be fixed with the slider, and passes through carriage release lever and expansion bracket connected on the right of the slider, the plug is fixed with base and dead lever at the back. This road construction road bed measuring apparatu rinses the inside evenly distributed of cover has the brush, and the length of brush is greater than the measuring stick and the internal clearance length of rinsing the cover, and the brush that passes through that from this can be fine reaches and carries out rough abluent effect, secondary measurement of also being convenient for simultaneously to the intact measuring stick that speckles with earth of firm measurement.