After adding a coagulant, the sludge undergoes a thorough mixing reaction and flows into the feed distributor of the concentration section. The sludge is evenly distributed on the inclined concentration section, and under the bi-directional drainage and gravity of the mud rake, the sludge quickly removes its free water with the movement of the filter cloth. After gravity dewatering, the concentrated sludge reversing mechanism transports the sludge to the gravity dewatering section of the belt filter press for further dewatering. Then it is fed into the "s" - shaped pressing section, where the sludge is sandwiched between the upper and lower layers of filter cloth. It is repeatedly pressed by several rollers of different diameters, causing the sludge cake to dehydrate again. Finally, the sludge cake is scraped off by a scraper, and the upper and lower mesh belts are automatically cleaned continuously during operation. This machine has the characteristics of high production capacity and high sludge dewatering rate. Widely used in municipal sludge, tailings, alcohol waste liquid, coal slurry from coal washing plants, paper mill sludge, slaughterhouse sludge, car wash sludge, and sludge generated in various sewage treatment processes.