The invention discloses a concentration dewatering filter pressing device for solidifying sludge. The device comprises a main box body and an external traction piece arranged at the upper end of the main box body, the main box body comprises a feeding mechanism arranged on one side of the main box body, an external connection mechanism arranged on the other side of the main box body, and a pressure guide mechanism arranged in the main box body, and one end of the pressure guiding mechanism is connected with the external traction piece. Clean water is added into an air bag, the air bag becomes larger slowly, an electromagnetic adsorption plate gets close to a brake magnetic block slowly, meanwhile, current is connected into the electromagnetic adsorption plate, the electromagnetic adsorption plate has magnetism opposite to that of the brake magnetic block, and therefore suction force is generated, the brake magnetic block is attracted, the brake magnetic block moves along a penetrating rod, a main pipe is loosened, a pressing cylinder falls into a placing cylinder, sludge filter pressing is completed, and the filter pressing effect is good.