The utility model discloses a silting-proof sludge drainage device which comprises a water drainage body pressed in sludge. The drainage body is in a shape of a cylinder and comprises a frame. Plastic blind ditches are filled inside a frame cylindrical portion, a tooth-shaped sleeve is fixedly connected with one end portion of the frame cylindrical portion, filtering cloth is wrapped on the rest cylindrical portions of the frame, and the filtering cloth is fixedly connected with the tooth-shaped sleeve. A sealing end plate is respectively arranged at two ends of the frame, and the drainage body is connected with two hard vacuum pipes at two ends through the sealing end plates in rotating mode. Air sucking ports of the hard vacuum pipes are arranged in a hollow structure of the drainage body, and air discharging ports are connected with an external vacuum air sucking device. The tooth-shaped sleeve is connected with an external motor through a transmission belt. A brush is arranged on the portion of the drainage body wrapped in the filtering cloth. The silting-proof sludge drainage device can guarantee efficiency of the drainage body at any time, is simple in structure, light, easy to operate and high in efficiency.