The invention discloses a slurry dehydrator. The slurry dehydrator comprises a conveyor and a low-pressure-stage dehydration device; the low-pressure-stage dehydration device comprises a plurality ofrolling shafts and filtering nets arranged on the rolling shafts; the central shafts of the plurality of rolling shafts form an arc-shaped surface; and the conveyor is used for conveying slurry to thelow-pressure-stage dehydration device. The low-pressure-stage dehydration device also comprises the filtering nets, the slurry can be conveyed to the low-pressure-stage dehydration device through theconveyor, and the plurality of rolling shafts of the low-pressure-stage dehydration device form an arc shape, so the slurry with flowability is dehydrated, the slurry is filtered through the filtering nets on the plurality of rolling shafts, and water is removed, so that the dehydration effect is achieved, and the dehydration principle and the dehydration rate are high.