The invention discloses membrane filter plates used for electro-osmosed sludge, a membrane filter press and a filter press. Each membrane filter plate is also provided with a relatively sealed membrane cavity formed by two membrane plates, wherein the membrane cavities are communicated with pressing water pipes; solid plates are arranged in the middle of the membrane cavities; filter cloths are arranged on the two sides of the membrane filter plates; cathode conductive filter screens are arranged on the backs of the filter cloths as liners and are connected with a cathode copper bar; grids of the cathode conductive filter screens are fit with sunk areas of the membrane filter plates; units are formed by the two parallel cathode membrane filter plates and form a relatively sealed sludge storage cavity; the sludge storage cavity is separated into two independent spaces by an anode plate connected with an anode copper bar. A sludge electro-osmotic dewatering device has a simple structure, operates reliably, can achieve reduction of the moisture content of the sludge below 50%, and improves the dewatering efficiency by 2-3 times compared with the membrane filter press.