The invention discloses an electroosmosis and pressure filtration coupled sewage sludge dehydrating device, which comprises a pressure filtration container (1), an anode plate (2), a cathode plate (3) and a direct-current power supply (4), wherein the anode plate (2) is arranged at the upper part of the pressure filtration container (1); the cathode plate (3) is arranged at the lower part of the pressure filtration container (1); a positive electrode and a negative electrode of the direct-current power supply (4) are electrically connected with the anode plate (2) and the cathode plate (3) respectively; the anode plate (2) and the cathode plate (3) are both provided with water outlet holes (5); filter clothes (5.1) are laid on the water outlet holes (5); the anode plate (3) is connected with a hydraulic system (6) used for driving the anode plate (3) to move. By adopting the electroosmosis and pressure filtration coupled sewage sludge dehydrating device, the resistance of sludge on an anode layer is increased slowly; the dehydration effect is good; the moisture content, in the thickness direction, of the sludge is uniformly distributed.