The invention discloses a dehydrating and filter-pressing device for slurry. The device comprises hydraulic cylinders for supplying power, wherein a supporting platform is arranged on a filter-pressing container; four mounting blocks are fixed to the supporting platform and are positioned at four corners of the filter-pressing container; a hinging hole is formed in each mounting block; four hydraulic cylinders are correspondingly mounted on the hinging holes in the mounting blocks through bolts; a pair of the two hydraulic cylinders are connected to the same filter-pressing sheet through hydraulic rods; two filter-pressing sheets are positioned in the filter-pressing container. With the adoption of the device, the problem of complex structure of an existing device and complex dehydrating and filter-pressing process and hard control can be solved; the quantity of raw materials processed by once filter-pressing hydrating can be increased, so that the compressing effect is improved, and the filter-pressing efficiency is improved; the durability of the whole device is improved; the device has the advantages of being obvious in filter-pressing dehydrating effect, high in structure stability, and high in operability.