Adjusting device used before laying and fixing of rails

The invention discloses an adjusting device used before laying and fixing of rails. The adjusting device aims at overcoming the defects that during existing adjustment of rail laying, common crow bars, wedges and hammers are used by workers for knocking, and consequently the mounting precision cannot be guaranteed, work efficiency is low, the labor intensity is high, and safety accidents are prone to occurring. A vertical adjusting screw with the lower end provided with a rail clamp is mounted on a fixed portal cross beam which stretches across a rail foundation beam; an upper transverse screw connected with a screw body of the vertical adjusting screw in a perpendicular crossing mode is transversely mounted under a cross beam of portal stand columns; and two lower transverse screws with central lines facing an I-shaped lower beam of each rail are transversely mounted on the stand columns at the two sides of a portal and located under the upper transverse screw, and clamp heads are fixed to the opposite ends