After concentrated sludge is mixed with a certain concentration of flocculant in static and dynamic mixers, tiny solid particles in the sludge agglomerate into larger flocculent clumps while separating free water. The flocculated sludge is then conveyed onto a gravity-dewatering filter belt, where under the force of gravity, free water is separated, forming a non-flowing sludge. This sludge is then sandwiched between two mesh belts and is gradually pressed under increasing pressure and shear force through a wedge-shaped pre-compression zone, low-pressure zone, and high-pressure zone, maximizing the separation of sludge and water, ultimately forming a filter cake that is discharged. This machine is suitable for sludge dewatering in municipal wastewater treatment plants, pharmaceuticals, electroplating, papermaking, leather, dyeing, metallurgy, chemicals, slaughterhouses, food processing, brewing, coal washing, and environmental protection projects. It is also ideal for solid-liquid separation in industrial production, making it excellent for environmental remediation and resource recovery.