The invention discloses a gravel purifier. The gravel purifier comprises a crawler conveyer, wherein a rack is arranged on the upper part of the crawler conveyer; a linear sieve is arranged on the rack; a horizontal spiral conveyer is arranged above the linear sieve; a drum sieve is arranged above the horizontal spiral conveyer; an inclined support is arranged at one side of the rack; a spiral conveyer for loading is arranged on the inclined support; and a material bin is arranged at the bottom of the spiral conveyer for loading. The gravel purifier disclosed by the invention has the beneficial effects of being capable of rapidly and efficiently filtering and grading gravel in a sand pit, high in production efficiency, and high in processing speed.